View source for Transportation in the United States

{{Short description|none}}
{{Use American English|date=May 2015}} 
{{Use mdy dates|date=September 2019}}
{{Economy of the United States sidebar}}
The vast majority of passenger travel in the [[United States]] occurs by automobile for shorter distances and airplane or railroad for longer distances. Most cargo in the U.S. is transported by, in descending order, railroad, truck, pipeline, or boat; [[air shipping]] is typically used only for perishables and premium express shipments. Transportation is the largest source of [[greenhouse gas emissions by the United States|greenhouse gas emissions in the United States]].

==Ownership and jurisdiction==
The overwhelming majority of roads in the United States are owned and maintained by state and local governments.  Federally maintained roads are generally found only on federal lands (such as [[List of National Parks of the United States|national parks]]) and at federal facilities (like military bases).  The [[Interstate Highway System]] is partly funded by the federal government but owned and maintained by individual state governments.  There are a few [[private highways in the United States]], which use tolls to pay for construction and maintenance.  There are many local [[private road]]s, generally serving remote or insular residences.

Passenger and freight rail systems, bus systems, water ferries, and dams may be under either public or private ownership and operation. Civilian airlines are all privately owned. Most airports are owned and operated by local government authorities, but there are also some private airports.  The [[Transportation Security Administration]] has provided security at most major airports since 2001.

The [[United States Department of Transportation|U.S. Department of Transportation]] and its divisions provide regulation, supervision, and the federal funding portion for all aspects of transportation, except for customs, immigration, and security, which are the responsibility of the [[United States Department of Homeland Security|U.S. Department of Homeland Security]].  Federal funding is typically allocated by a five-year [[transportation bill]]. Each state has [[List of U.S. state and insular area departments of transportation|its own Department of Transportation]], which builds and maintains state highways, and depending upon the state, may either directly operate or supervise other modes of transportation.

[[Aviation law]] is almost entirely the jurisdiction of the [[Federal government of the United States|U.S. federal government]]; the [[Federal Aviation Administration]] regulates all aspects of [[civil aviation]], [[air traffic management]], certification and compliance, and [[aviation safety]].

Motor vehicle traffic laws are enacted and enforced by state and local authorities, with the exception of roads located on federal property (such as national parks and military bases) or in the [[Territories of the United States|unorganized U.S. territories]].

The [[United States Coast Guard]] is the primary enforcer of law and security on U.S. waterways, inland as well as coastal, but economic jurisdiction over coastal [[tidelands]] is shared between state and federal governments.

==Mode share==
[[File:USCommutePatternsCarAlone.png|thumb|In most but not all American cities, the majority of work commutes are made by singly occupied automobiles.]]

===Passenger===
{| class="wikitable floatright"
|-
! Mode of passenger transport
! Passenger-miles<br />(millions)
! Percent
|-
| '''Highway&nbsp;— total'''
| style="text-align:right;"| '''4,273,876'''
| style="text-align:right;"| '''86.93%'''
|-
| [[Passenger vehicles]], [[motorcycles]]
| style="text-align:right;"| 3,692,760
| style="text-align:right;"| 75.11%
|-
| [[Trucks]]
| style="text-align:right;"| 268,318
| style="text-align:right;"| 5.46%
|-
| [[Buses]]
| style="text-align:right;"| 312,797
| style="text-align:right;"| 6.36%
|-
| '''Air Carriers'''
| style="text-align:right;"| '''580,501'''
| style="text-align:right;"| '''11.81%'''
|-
| '''Rail&nbsp;— total'''
| style="text-align:right;"| '''37,757'''
| style="text-align:right;"| '''0.77%'''
|-
| [[Public transport|Transit]]
| style="text-align:right;"| 19,832
| style="text-align:right;"| 0.40%
|-
| Commuter
| style="text-align:right;"| 11,121
| style="text-align:right;"| 0.23%
|-
| Intercity/[[Amtrak]]
| style="text-align:right;"| 6,804
| style="text-align:right;"| 0.14%
|-
| '''All other modes (e.g., [[ferryboats]])'''
| style="text-align:right;"| '''4,156'''
| style="text-align:right;"| 0.08%
|-
|colspan=3|<small>Source: 2012 estimates by the Bureau of Transportation Statistics<ref name=bts1>{{cite web |title=Table 1-40: U.S. Passenger-Miles (Millions) |url=http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_01_40.html |publisher=Bureau of Transportation Statistics, US Department of Transportation |access-date=December 5, 2014 |archive-date=December 4, 2014 |archive-url=https://web.archive.org/web/20141204233914/http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_01_40.html |url-status=dead }}</ref></small>
|}
Passenger [[transport]]ation is dominated by a network of over 3.9 million miles of highways<ref>{{cite web
|url=http://www.bts.gov/publications/national_transportation_statistics/html/table_01_01.html
|title=Table 1-1: System Mileage Within the United States
|access-date=March 12, 2008
|publisher=Bureau of Transportation Statistics
|work=National Transportation Statistics
|archive-url=https://web.archive.org/web/20080418081336/http://www.bts.gov/publications/national_transportation_statistics/html/table_01_01.html
|archive-date=April 18, 2008
|url-status=dead
}}</ref> which is pervasive and highly developed by global standards. Passenger transportation is dominated by [[passenger vehicles]] (including [[cars]], [[trucks]], vans, and [[motorcycles]]), which account for 86% of [[passenger-mile]]s traveled. The remaining 14% was handled by [[Airplane|planes]], [[trains]], and [[buses]].<ref name=btsPM>{{cite web
|url=http://www.bts.gov/publications/pocket_guide_to_transportation/2008/html/table_04_03.html
|title=Table 4-3 Passenger-Miles: 1990-2005
|access-date=March 12, 2008
|publisher=Bureau of Transportation Statistics
|work=Pocket Guide to Transportation
|archive-date=August 21, 2008
|archive-url=https://web.archive.org/web/20080821165448/http://www.bts.gov/publications/pocket_guide_to_transportation/2008/html/table_04_03.html
|url-status=dead
}}</ref><ref>A "passenger-mile" is one passenger transported one mile. For example, one vehicle traveling 3 miles carrying 5 passengers generates 15 passenger-miles.</ref> Public transit use is highly concentrated in large older cities, with only six above 25% and only New York City above 50% of trips on transit. Airlines carry almost all non-commuter intercity traffic, except the [[Northeast Corridor]] where Amtrak carries more than all airlines combined.

The world's second largest automobile market,<ref>{{cite web|title = Pollfish: Insights from the largest car purchase intent study in US|url = https://www.pollfish.com/infographic/car|website=Pollfish.com|access-date = December 29, 2015|archive-date = March 4, 2016|archive-url = https://web.archive.org/web/20160304151042/https://www.pollfish.com/infographic/car|url-status=dead}}</ref> the United States has the highest rate of per-capita vehicle ownership in the world, with 865 vehicles per 1,000 Americans.<ref>{{cite web |url=http://europa.eu/rapid/press-release_STAT-06-125_en.pdf |title=Car Free Day 2006: Nearly One Car per Two Inhabitants in the EU25 in 2004 |date=September 19, 2006 |publisher=Europa, Eurostat Press Office |access-date=October 27, 2015 |archive-date=March 5, 2016 |archive-url=https://web.archive.org/web/20160305084051/http://europa.eu/rapid/press-release_STAT-06-125_en.pdf |url-status=live}}</ref>

[[Cycling|Bicycle usage]] is minimal with the [[American Community Survey]] reporting that [[bicycle commuting]] had a 0.61% mode share in 2012 (representing 856,000 American workers nationwide).<ref>{{cite web |url=http://www.transalt.org/info/other/010901TQpdf021.pdf |author1=Pucher, John |author2=Lewis Dijkstra |name-list-style=amp |title=Making Walking and Cycling Safer: Lessons from Europe |date=February 2000 |publisher=Transportation Alternatives |work=Transportation Quarterly |access-date=August 15, 2007 |archive-url=https://web.archive.org/web/20070925184323/http://www.transalt.org/info/other/010901TQpdf021.pdf |archive-date=September 25, 2007 |url-status=dead}}</ref><ref>{{cite web | url = https://psmag.com/social-justice/commuting-bike-way-last-year-68509 | author = Herman, Marc | title = Commuting by Bike Was Way Up Last Year | date = October 2013 | publisher = Pacific Standard | access-date = November 7, 2013 | archive-date = April 4, 2018 | archive-url = https://web.archive.org/web/20180404134935/https://psmag.com/social-justice/commuting-bike-way-last-year-68509 |url-status=live}}</ref>

===Cargo===
{| class="wikitable floatright"
|-
! Mode of Freight Shipments !! 2011 Ton miles<br/>(billions) !! Percent of Total
|-
| Truck || style="text-align:right;" | 2,337 || style="text-align:right;" | 40.24%
|-
| Rail || style="text-align:right;" | 1,518 || style="text-align:right;" | 26.13%
|-
| Water || style="text-align:right;" | 434 || style="text-align:right;" | 7.47%
|-
| Air & Air/Truck || style="text-align:right;" | 11 || style="text-align:right;" | 0.19%
|-
| Pipeline || style="text-align:right;" | 1,018 || style="text-align:right;" | 17.53%
|-
| Multiple modes || style="text-align:right;" | 489 || style="text-align:right;" | 8.43%
|-
| Other & Unknown || style="text-align:right;" | 93 || style="text-align:right;" | 1.60%
|-
| Total || style="text-align:right;" | 5,807 || style="text-align:right;" | 100%
|-
|colspan=3|<small>Source: 2011 estimates by the Bureau of Transportation Statistics<ref name=bts2>{{cite web
|url=http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/pocket_guide_to_transportation/2014/3_Moving_Goods/table3_1
|title=3-1 Freight Shipments Within the U.S. by Mode
|access-date=June 11, 2014
|publisher=Bureau of Transportation Statistics
|archive-date=July 14, 2014
|archive-url=https://web.archive.org/web/20140714115722/http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/pocket_guide_to_transportation/2014/3_Moving_Goods/table3_1
|url-status=dead
}}</ref></small>
|}

[[Freight transport|Freight transportation]] is carried by a variety of networks. The largest percentage of US freight is carried by trucks (60%), followed by pipelines (18%), rail (10%), ship (8%), and air (0.01%).<ref>{{cite web |url=https://www.bts.gov/archive/publications/freight_in_america/table_01 |title=Table 1 – Commercial Freight Activity in the United States by Mode of Transportation: 2002 |access-date=October 27, 2015 |publisher=US Bureau of Transportation Statistics |work=Freight in America |archive-date=June 7, 2017 |archive-url=https://web.archive.org/web/20170607032112/https://www.bts.gov/archive/publications/freight_in_america/table_01 |url-status=live}}</ref> Other modes of transportation, such as [[Package delivery|parcel]]s and [[Intermodal freight transport|intermodal]] freight accounted for about 3% of the remainder. Air freight is commonly used only for perishables and premium express shipments. The difference in percentage of rail's share by [[ton-mile]]s and by weight (10% vs 38%) is accounted for by the extreme efficiency of trains. A single railroad locomotive may pull fifty boxcars full of freight while a truck only pulls one. Trucks surpass trains in the weight category due their greater numbers, while trains surpass trucks in the ton-miles category due to the vast distances they travel carrying large amounts of freight.

Usually cargo, apart from petroleum and other bulk commodities, is imported in [[containerization|containers]] through seaports, then distributed by road and rail.  The quasi-governmental [[United States Postal Service]] has a monopoly on letter delivery (except for express services) but several large private companies such as [[FedEx]] and [[United Parcel Service|UPS]] compete in the package and cargo delivery market.

<gallery widths=280px heights=240px>
Freight flows by highway, railway, and waterway.webp|Freight flows by: {{legend-line|#AF227A solid 4px|[[Interstate Highway System|Interstate-Highways]]}} {{legend-line|#A5A5A5 solid 4px|[[Numbered highways in the United States|Highways]]}} {{legend-line|#00BF4C solid 4px|[[Rail transportation in the United States|Railways]]}} {{legend-line|#195AB0 solid 4px|[[Inland waterways of the United States|Inland waterways]]}}
File:Freight Transport volumes of USA.svg|Freight Transport volumes (Tonne-Kilometers)
</gallery>

==Safety==
{{Further|Transportation safety in the United States}}
[[File:Eastern Washington Truck.jpg|thumb|A transport truck in [[Eastern Washington]]]]
The U.S. government's National Center for Health Statistics reported 33,736 motor vehicle traffic deaths in 2014. This exceeded the number of firearm deaths, which was 33,599 in 2014.

In 2020 there was {{#expr:(38680/18000-1)*100 round 0}}% more road fatalities in the US than in the European Union, or {{#expr:(1-18000/38680)*100 round 0}}% less in the EU than in the US, with nearly 38,680 in the US,<ref>{{cite web |last=Guzman |first=Joseph |url=https://thehill.com/changing-america/well-being/556852-traffic-deaths-spiked-in-2020-despite-pandemic |title=Traffic deaths spiked in 2020 despite pandemic |publisher=TheHill |date=2021-06-04 |accessdate=2021-11-26 |archive-date=June 5, 2021 |archive-url=https://web.archive.org/web/20210605073243/https://thehill.com/changing-america/well-being/556852-traffic-deaths-spiked-in-2020-despite-pandemic |url-status=live}}</ref> and nearly 18,800 in the EU.<ref>{{cite web |last=Damiani |first=Anne |url=https://www.euractiv.com/section/road-safety/news/eu-has-worlds-safest-roads-recorded-fewest-traffic-related-deaths-in-2020/ |title=EU has world's safest roads, recorded fewest traffic-related deaths in 2020 – |publisher=Euractiv.com |date=2021-04-20 |accessdate=2021-11-26 |archive-date=June 5, 2021 |archive-url=https://web.archive.org/web/20210605074708/https://www.euractiv.com/section/road-safety/news/eu-has-worlds-safest-roads-recorded-fewest-traffic-related-deaths-in-2020/ |url-status=live}}</ref>

{| class="wikitable nowrap" style="text-align:right;"
|+U.S. passenger fatalities per billion passenger-miles<br />2002-2007<ref>Bureau of Transportation Statistics, [http://www.bts.gov/publications/national_transportation_statistics/pdf/entire.pdf National Transportation Statistics] {{Webarchive|url=https://web.archive.org/web/20100407145906/http://www.bts.gov/publications/national_transportation_statistics/pdf/entire.pdf |date=April 7, 2010 }}. Passenger-miles by mode: Table 1-40, p. 74. Air and car fatalities: Table 2-1, p. 125. Transit fatalities: Table 2-32, p. 168. Railroad fatalities: Table 2-39, p. 181.  Only fatalities among on-board passengers are counted.</ref>
|- style="text-align:center;"|
!Mode || Passenger<br />fatalities || Passenger-miles<br />(millions) || Fatalities<br />per billion<br /> miles
|-
| style="text-align:left;"|Passenger {{wbr}}car
| 127,124
| 15,958,620 M
| 7.97
|-
| style="text-align:left;"|Light rail
| 79
| 9,980 M
| 7.92
|-
| style="text-align:left;"|Motor bus
| 399
| 117,982 M
| 3.38
|-
| style="text-align:left;"|Commuter {{wbr}}rail
| 105
| 59,736 M
| 1.76
|-
| style="text-align:left;"|Heavy rail {{wbr}}(subway)
| 106
| 86,900 M
| 1.22
|-
| style="text-align:left;"|Railroad {{wbr}}(intercity)
| 36
| 33,234 M
| 1.08
|-
| style="text-align:left;"|Airline
| 113
| 3,326,286 M
| 0.03
|}

{|
|-
!Road fatalities, comparison with Europe
|-
|{{Graph:Chart |width=400 |height=200 |xAxisTitle=Year |yAxisTitle=Deaths |legend= |type=line 
|x=1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
|y1= 44599, 44508, 39250, 40150, 40716, 41817, 42065,  42013,  41501,  41717,  41945,  42116,  42815,  42884,  42836,  43510,  42708,  41259,  37423,  33883,  32999,  32479,  33783,  32894,  32744, 35484, 37806
|y2= ,76200, 71500, 66200, 64700, 64000, 60100, 61000, 59600, 58400, 57080, 54900, 53300, 50400, 47300, 45300, 43100,  42500, 38900,  34800, 31500, 30685, 28243, 25956, 25977, 26130, 25651                        
|xType=date
|xAxisFormat=%Y
|xAxisAngle=-40
|yType=integer
|yAxisFormat=s
|y1Title=United-States
|y2Title=European Union
|yAxisMin=0 
|yGrid= 
}}
|-
| colspan=2 |
* UE: Source UE<ref>SÉCURITÉ ROUTIÈRE: Quelle est la situation dans votre pays?
ec.europa.eu/transport/road_safety/pdf/statistics/dacota/scoreboard_2015_en.pdf
D'après des données CARE/Eurostat</ref><ref>Annual Accident Report 2018 https://ec.europa.eu/transport/road_safety/sites/roadsafety/files/pdf/statistics/dacota/asr2018.pdf {{Webarchive|url=https://web.archive.org/web/20190602124428/https://ec.europa.eu/transport/road_safety/sites/roadsafety/files/pdf/statistics/dacota/asr2018.pdf |date=June 2, 2019 }}</ref>
* United-States: Source OCDE/ITF<ref name="IRTAD">Base de donénes IRTAD_CASUAL_BY_AGE stats.oecd.org/Index.aspx?DataSetCode=IRTAD_CASUAL_BY_AGE</ref> for 1990, 2000 and 2010-2015 period (killed after 30 days)
|}

==History==
[[File:A reference history of the world from the earliest times to the present; part one- world history, part two- national histories; maps, tables, charts, and an exhaustive index (1921) (14770451411).jpg|thumb|A 1921 illustration of deer, oxen, dog, alpaca, horse, railroad, and automobile transport]]

===18th century===
In the late 18th century, overland transportation was by horse, while water and river transportation was primarily by sailing vessel. The United States population was centered on its [[East Coast of the United States|Atlantic coast]], with all major population centers located on a natural harbor or navigable waterway.  Low population density between these centers resulted in a heavy reliance on coastwise and [[riverboat]] shipping. 

The first government expenditures on highway transportation were funded to speed the delivery of overland mail, such as the [[Boston Post Road]] between [[New York City]] and [[Boston]]. Due to the distances between these population centers and the cost to maintain the roads, many highways in the late 18th century and early 19th century were private [[Toll road|turnpikes]]. 

Other highways were mainly unimproved and impassable by wagon at least some of the year.  Economic expansion in the late 18th century to early 19th century spurred the building of canals to speed goods to market. One such prominent example was the [[Erie Canal]].

=== 19th century ===
Numerous modes of transportation fought for supremacy throughout the [[Industrial Revolution|Industrial revolution]] of the 19th century. Canals swiftly took the role of turnpikes, [[stagecoach]]es, and wagon routes, which in turn were shortly replaced by [[Steamboat|steam-powered riverboats]]. During this period, the advancement in transportation inspired many artists to display the grand contrast from the past to the new. Taking a look at [[Samuel Colman]]'s work, one piece in particular, ''Storm King on the Hudson'' (1866)[https://americanart.si.edu/artwork/storm-king-hudson-5183] displayed both the older sailboats and the grand [[steamboat]]s that were overtaking the [[Hudson River]].

Access to water transportation shaped the geography of early settlements and boundaries.  For example, the [[Erie Canal]] escalated the boundary dispute called the [[Toledo War]] between Ohio and Michigan in the 1830s.  The disputed [[Erie Triangle]] was awarded to [[Pennsylvania]], giving that state access to [[Lake Erie]].  Most of [[West Florida]] was given to Mississippi and Alabama to guarantee their access to the [[Gulf of Mexico]].

Development of the mid-western and southern states drained by the Mississippi River system ([[Mississippi River|Mississippi]], [[Ohio River|Ohio]] and [[Missouri River]]s) was accelerated by the introduction of [[Steamboats of the Mississippi|steamboats]] on these rivers in the early 19th Century.  These three rivers ([[List of river borders of U.S. states|among others]]) also form the borders of several states.  Prior to the introduction of steamboats, transit upstream was impractical because of strong currents on parts of these waterways.  Steamboats provided both passenger and freight transportation until the development of railroads later in the 19th Century gradually reduced their presence.

The rapid expansion of [[Rail transport in the United States#History|railroads]] brought the canal boom to a sudden end, providing a quick, scheduled and year-round mode of transportation that quickly spread to interconnect the states by the mid-19th century.  During the [[industrialization]] of the United States after the [[American Civil War|Civil War]], railroads, led by the [[First transcontinental railroad|transcontinental rail system]] in the 1860s, expanded quickly across the United States to serve industries and the growing cities.  During the late 19th century, railroads often had built redundant routes to a competitor's road or built through sparsely populated regions that generated little traffic. These marginal rail routes survived the pricing pressures of competition, or the lack of revenue generated by low traffic, as long as railroads provided the only efficient economical way to move goods and people across the United States.  In addition to the intercity passenger network running on Class I and II railroads, a large network of [[interurban]] ([[Tram|trolley]] or "street running") rail lines extended out from the cities and interchanged passenger and freight traffic with the railroads and also provided competition.

===20th century===
{{Further|Great American streetcar scandal}}
[[File:Jane M. Byrne Interchange 4-1-22.jpg|thumb|The [[Jane Byrne Interchange]] in [[Chicago Loop|downtown Chicago]]]]
The advent of the [[automobile]] signaled the end of railroads as the predominant transportation for people and began a new era of mobility in the United States. The early 20th century [[Lincoln Highway]] and other [[auto trail]]s gave way in the 1920s to an early [[United States Numbered Highways|national highway]] system making the automobile the primary mode of travel for most Americans.  [[Interurban]] rail service declined, followed by [[trolley car]]s due in part to the advent of motorized buses and the lack of dedicated rights-of-way but also by deliberate efforts to dismantle urban rail infrastructure.

The scarcity of industrial materials during [[World War II]] slowed the growth of automobile manufacturing briefly and contributed to the nation's declining rail network. In the 1950s, however, the United States renewed building a network of high-capacity, high-speed [[highway]]s to link its vast territory. The most important element is the [[Interstate Highway]] system, first commissioned in the 1950s by President [[Dwight D. Eisenhower]] and modeled partly after the Italian [[Autostrade of Italy|autostrada]] and the German [[Autobahn]] system.

By 1945, after the end of [[World War II]], nearly every city in America had at least one electric tram company providing intra-city transportation. There were an estimated 36,377 light rail vehicles in operation. Increased automobile ownership cut this number by 1/3 by 1965.<ref>{{Cite news | first=Ben | last=Vient | title=Speeding to reverse in Alicante, Spain | newspaper=Florida Today | location=Melbourne, Florida| pages= 6E | date=February 28, 2016 }}</ref><!---says nothing about when this number was reduced to zero--->

The airline industry began to successfully compete with intercity rail as a result of government investment, which suffered a loss of ridership. As the civil air transportation network of [[airport]]s and other infrastructure expanded, air travel became more accessible to the general population.  Technological advances ushered in the [[jet age]], which increased airline capacity, while decreasing travel times and the cost of flights.  The costs of flying rapidly decreased [[intercity rail]] ridership by the late 1960s to a point where railroads could no longer profitably operate networks of passenger trains.{{clarify|passenger trains were never profitable! They were required by the government as part of each railroad having a monopoly in a given area. Once this was eliminated, passenger trains evaporated almost overnight|date=November 2015}} By the early 1970s almost all passenger rail operation and ownership had been transferred to various federal, municipal and state agencies.

Freight railroads continued to decline as motor freight captured a significant portion of the less-than-carload business. This loss of business, when combined with the highly regulated operating environment and constrained [[pricing power]], forced many railroads into receivership and the nationalization of several critical eastern carriers into the [[Consolidated Rail Corporation]] (Conrail). Deregulation of the railroads by the [[Staggers Act]] in 1980 created a regulatory environment more favorable to the economics of the railroad industry.

In the 1990s, the increase in foreign trade and intermodal container shipping led to a revival of the freight railroads, which have effectively consolidated into two eastern and two western private transportation networks: [[Union Pacific]] and [[BNSF]] in the west, and [[CSX]] and [[Norfolk Southern]] in the east.  [[Canadian National Railway]] took over the [[Illinois Central]] route down the Mississippi River valley.

===21st century===
In 2014, [[freight transportation]] establishments serving for-hire transportation and warehousing operations employed nearly 4.6 million workers and comprised 9.5 percent of the Nation's economic activity as measured by GDP. Truck driving is by far the largest freight transportation occupation, with approximately 2.83 million truck drivers. About 57.5 percent of these professional truck drivers operate heavy or [[Semi-trailer truck|tractor-trailer trucks]] and 28.2 percent drive light or delivery service trucks.<ref name="autogenerated1">{{cite web |url=https://ops.fhwa.dot.gov/freight/infrastructure/nfn/rptc/cp23hwyfreight/iii_ch11.htm#fn1 |title=Status of the Nation's Highways, Bridges, and Transit Conditions and Performance |date=May 23, 2018 |access-date=September 12, 2020 |archive-date=October 18, 2020 |archive-url=https://web.archive.org/web/20201018025330/https://ops.fhwa.dot.gov/freight/infrastructure/nfn/rptc/cp23hwyfreight/iii_ch11.htm#fn1 |url-status=live}}</ref>

According to ''Freight Facts and Figures 2015'', U.S. freight transportation system handled a record amount of freight in 2014. A daily average of approximately 55 million tons of freight valued at $49.3 billion moved across the transportation system in 2014 to meet the needs of the nation's 122.5 million households, 7.5 million business establishments, and 90,056 Government units.<ref name="autogenerated1"/>

Wartime expediency encouraged long distance [[pipeline transport]] of petroleum and natural gas, which was greatly expanded in the middle 20th century to take over most of the domestic long-haul market.

==Road transportation==
{{Further|Driving in the United States|Automotive industry in the United States}}

===Infrastructure and private automobile use===
{{Further|Numbered highways in the United States}}
[[File:Map of current Interstates.svg|thumb|The [[Interstate highway]] system in the United States is the largest national [[controlled-access highway]] network in the world.]]
{{multiple image
 | direction = horizontal
 | total_width = 400
 | image1 = US Speed Limits.svg
 | image2 = Speed_limits_territories2.png
 | caption1 = Maximum [[speed limits in the United States|speed limits in the U.S. states]] vary by state from 60 to 85 mph. |caption2=Maximum speed limits in the [[Territories of the United States|U.S. territories]] vary by territory from 15 to 65 mph.
}}
In comparison to some parts of the [[Western world]], both the United States and Canada rely more heavily on motorized transit over walking and bicycling<ref>{{cite web |url=http://onlinepubs.trb.org/onlinepubs/trnews/trnews280WesternEurope.pdf|title=Walking and Cycling in Western Europe and the United States|website=Onlinepubs.trb.org|access-date=October 14, 2017|archive-date=June 23, 2017 |archive-url=https://web.archive.org/web/20170623020112/http://onlinepubs.trb.org/onlinepubs/trnews/trnews280westerneurope.pdf |url-status=live}}</ref> with 86% of American workers commuting to work via private vehicle,<ref>{{cite web |url=https://www.census.gov/library/publications/2015/acs/acs-32.html|title=Who Drives to Work? Commuting by Automobile in the United States: 2013|publisher=US Census Bureau |access-date=October 14, 2017|url-status=live|archive-date=May 24, 2017|archive-url=https://web.archive.org/web/20170524113634/https://census.gov/library/publications/2015/acs/acs-32.html}}</ref><ref>{{cite web|url=http://www.altrans.net/pdfs/acs.pdf |title=ABCD|website=Altrans.net|access-date=October 14, 2017|archive-date=April 12, 2019|archive-url=https://web.archive.org/web/20190412095322/http://www.altrans.net/pdfs/acs.pdf|url-status=live}}</ref> costing an estimated additional $1500 per year commuting compared to Western European counterparts.<ref>{{cite web |url=http://bigthink.com/stefani-cox/us-commuters-are-pretty-different-from-commuters-in-other-countries |title=How U.S. Commuters Differ from Commuters in Other Countries|first=Stefani|last=Cox|website=Bigthink.com |date=June 14, 2016 |access-date=October 14, 2017|archive-date=October 12, 2017 |archive-url=https://web.archive.org/web/20171012202502/http://bigthink.com/stefani-cox/us-commuters-are-pretty-different-from-commuters-in-other-countries|url-status=live}}</ref>  Car ownership is on the decline<ref name="umich.edu">{{cite web |url=http://ns.umich.edu/new/releases/21923-hitchin-a-ride-fewer-americans-have-their-own-vehicle|title=Hitchin' a ride: Fewer Americans have their own vehicle |website=University of Michigan News |date=January 23, 2014 |access-date=October 14, 2017|archive-date=September 30, 2017|archive-url=https://web.archive.org/web/20170930001412/http://ns.umich.edu/new/releases/21923-hitchin-a-ride-fewer-americans-have-their-own-vehicle|url-status=live}}</ref> but still 91% nationally.<ref>{{cite web|url=https://qz.com/873704/no-car-households-are-becoming-more-common-in-the-us-after-decades-of-decline/|title=After decades of decline, no-car households are becoming more common in the US|first=Dave |last=Gershgorn|website=Qz.com|date=December 28, 2016 |access-date=October 14, 2017|archive-date=October 12, 2017|archive-url=https://web.archive.org/web/20171012201932/https://qz.com/873704/no-car-households-are-becoming-more-common-in-the-us-after-decades-of-decline/|url-status=live}}</ref> Car ownership is universal, except in the largest cities where extensive [[mass transit]] and [[railroad]] systems have been built,<ref name="umich.edu"/> with lowest car ownership rates in [[New York City]] (44%), [[Washington, D.C.]] (62%), [[Boston]] (63%), [[Philadelphia]] (67%), [[San Francisco]] (69%), and [[Baltimore]] (69%).

With the development of the extensive [[Dwight D. Eisenhower|Eisenhower]] [[Interstate Highway System]] in the 1950s, both long distance trips and daily commutes were mostly by private [[automobile]]. This network was designed to exacting federal standards in order to receive federal funding. The system, {{as of|2010|lc=y}}, has a total length of {{convert|47182|mi|km}},<ref>{{cite report |department= Office of Highway Policy Information |publisher= Federal Highway Administration |url= https://www.fhwa.dot.gov/policyinformation/statistics/2010/hm20.cfm |title= Table HM-20: Public Road Length – 2010 |date= December 2011 |access-date= May 9, 2012 |archive-date= August 31, 2012 |archive-url= https://web.archive.org/web/20120831014910/http://www.fhwa.dot.gov/policyinformation/statistics/2010/hm20.cfm |url-status= live }}</ref> making it the world's second longest after [[Expressways of China|China]]'s, and the largest [[public works]] project in US history.<ref>{{cite web|url=http://www.tfhrc.gov/pubrds/06jan/01.htm|title=The Year of the Interstate|access-date=April 29, 2008|archive-url=https://web.archive.org/web/20100314065841/http://www.tfhrc.gov/pubrds/06jan/01.htm|archive-date=March 14, 2010|url-status=dead}}</ref>

The Interstate system joined an existing [[National Highway System (United States)|National Highway System]], a designation created for the legacy highway network in 1995, comprising 160,000 miles (256,000 kilometers) of roadway, a fraction of the total mileage of roads.  The Interstate system serves nearly all major U.S. cities, often through the [[downtown]] areas, which triggered [[freeway and expressway revolts]] in the 1960s and 1970s. The distribution of many goods and services involves Interstate highways at some point.<ref name=caltrans_50>{{cite web |url=http://www.dot.ca.gov/interstate/ |title=The Interstate Highway System Turns 50 |year=2006 |access-date=January 10, 2008 |author=Caltrans |archive-date=October 16, 2007 |archive-url=https://web.archive.org/web/20071016214412/http://dot.ca.gov/interstate/ |url-status=live}}</ref> Residents of American cities commonly use urban Interstates to travel to their places of work. The vast majority of long-distance travel, whether for vacation or business, is by the national road network;<ref>{{cite web |publisher=Bureau of Transportation Statistics |url=http://www.bts.gov/publications/national_transportation_statistics/2002/html/table_01_36.html |title=Table 1-36: Long-Distance Travel in the United States by Selected Trip Characteristics |year=1995 |access-date=December 21, 2006 |archive-url=https://web.archive.org/web/20061005133820/http://www.bts.gov/publications/national_transportation_statistics//2002/html/table_01_36.html |archive-date=October 5, 2006 |url-status=dead }}</ref> of these trips, about one-third (by the total number of miles driven in the country in 2003) utilize the Interstate system.<ref>{{cite web|publisher=Federal Highway Administration|url=http://www.fhwa.dot.gov/policy/ohim/hs03/htm/vm1.htm|title=Annual Vehicle Distance Traveled in Miles and Related Data|year=2003|access-date=December 21, 2006|archive-date=September 17, 2007|archive-url=https://web.archive.org/web/20070917013437/http://www.fhwa.dot.gov/policy/ohim/hs03/htm/vm1.htm|url-status=dead}}</ref>

In addition to the routes of the Interstate system, there are those of the [[United States Numbered Highways|U.S. highway system]]. These routes, which are unrelated to those of the National Highway System, are supplemented by [[State Highway]]s, and the local roads of [[County highway|counties]], municipal [[street]]s, and federal agencies, such as the [[Bureau of Indian Affairs]].  The five inhabited [[Territories of the United States|U.S. territories]] also have their own road networks. There are approximately {{convert|4,161,000|mi|km}} of roads in the United States, {{convert|2,844,000|mi|km}} paved and {{convert|1,317,000|mi|km}} unpaved.<ref>{{cite web |url=https://www.bts.gov/content/public-road-and-street-mileage-united-states-type-surfacea |title=Table 1-4: Public Road and Street Mileage in the United States by Type of Surface(a) (Thousands of miles) |publisher=Bureau of Transportation Statistics |access-date=August 11, 2022}}</ref> State highways are constructed by each state, but frequently maintained by county governments aided by funding from the state, where such counties exist as governing entities in mostly every state outside of the [[Northeastern United States|northeast]]. Counties construct and maintain all remaining roads outside cities, except in private communities. Local, unnumbered roads are often constructed by private contractors to local standards, then maintenance is assumed by the local government.<ref>{{cite web |url=http://www.naco.org/newsroom/pubs/Documents/NACo_Road_Ahead_02.24.2014.pdf |title=The Road Ahead: County Transportation Funding and Financing |access-date=September 19, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140701205643/http://www.naco.org/newsroom/pubs/Documents/NACo_Road_Ahead_02.24.2014.pdf |archive-date=July 1, 2014  }}</ref>

All federal [[highway]]s are maintained by state governments, although they receive federal aid to build and maintain [[freeway]]s signed as part of the 46,000 mile (75,000&nbsp;km) nationwide [[Interstate highway]] network. Changes by state initiative may be made with federal approval. A large number of expressways are actually government or privately operated [[toll road]]s in many East Coast and Midwestern states. West Coast freeways are generally free to users, which is the basis of their name, since freeways have no toll charged per use, although since the 1990s there have been some small experiments with toll roads operated by private companies.

After the collapse of the [[I-35W Mississippi River bridge]] in [[Minnesota]] in August 2007, the backlog of road and bridge maintenance across the country became an issue in transportation funding.<ref name="mpr">{{cite web |url=http://minnesota.publicradio.org/display/web/2012/08/01/daily-circuit-35w-bridge-infrastructure |title=5 years after I-35W bridge collapse, a look at nation's infrastructure |author=Kaiser, Emily |date=July 31, 2012 |access-date=October 27, 2015 |publisher=Minnesota Public Radio MPR News |archive-date=November 26, 2021 |archive-url=https://web.archive.org/web/20211126124658/https://www.mprnews.org/story/2012/08/01/daily-circuit-35w-bridge-infrastructure |url-status=live}}</ref> The collapse prompted a tax increase in Minnesota to speed up bridge repairs, and action in other states, such as the [[Massachusetts Department of Transportation#Accelerated Bridge Program|Accelerated Bridge Program]] in [[Massachusetts]], but after some debate no increase in federal funding.<ref name="mpr" />

The [[I-5 Skagit River bridge collapse]] in 2013, caused by a collision with an [[oversize load|over-height truck]], highlighted fracture critical bridges in which the failure of only one structural member will lead to complete collapse. According to the [[National Bridge Inventory]], there are at least 600,000 bridges of 20 feet or more in length in the United States, all subject to deterioration in the absence of preventative maintenance.<ref name=rdmbridges/> In December 2008, 72,868 bridges in the United States (12.1%) were categorized as "structurally deficient", representing an estimated $48 billion in repairs.  President [[Barack Obama]] proposed $50 billion of spending on road and bridge repair, plus a national infrastructure bank, but Congress did not act on these proposals.<ref>{{cite web |url=https://www.npr.org/2013/06/01/187599868/many-bridges-are-unsafe-but-few-agree-on-fixes |title=Many Agree Bridges Are Unsafe, But Few Agree On Fixes |publisher=NPR |date=June 1, 2013 |author=Naylor, Brian |access-date=October 27, 2015 |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304101957/http://www.npr.org/2013/06/01/187599868/many-bridges-are-unsafe-but-few-agree-on-fixes |url-status=live}}</ref>  President [[Donald Trump]] also failed to get infrastructure funding approved. In 2021, President [[Joe Biden]] signed a bipartisan infrastructure bill with about $110 billion for roads and bridges.<ref>{{cite news |last1=Ponciano |first1=Jonathan |title=Everything In The $1.2 Trillion Infrastructure Bill: New Roads, Electric School Buses And More |url=https://www.forbes.com/sites/jonathanponciano/2021/11/15/everything-in-the-12-trillion-infrastructure-bill-biden-just-signed-new-roads-electric-school-buses-and-more/?sh=73a7429f161f |access-date=19 November 2021 |work=Forbes |date=15 November 2021 |quote=Headlining the 2,702-page bill's spending, roughly $110 billion of new funds would go toward improving the nation's roads and bridges, and investments in other major transportation programs. |archive-date=November 19, 2021 |archive-url=https://web.archive.org/web/20211119023138/https://www.forbes.com/sites/jonathanponciano/2021/11/15/everything-in-the-12-trillion-infrastructure-bill-biden-just-signed-new-roads-electric-school-buses-and-more/?sh=73a7429f161f |url-status=live}}</ref>

As of 2010, [[Seat belt legislation in the United States|seat belt use is mandatory]] in all states except [[New Hampshire]].<ref name="seat_belt1">https://www.ghsa.org/state-laws/issues/Seat-Belts {{Webarchive|url=https://web.archive.org/web/20191210205201/http://www.ghsa.org/state-laws/issues/Seat-Belts |date=December 10, 2019 }} GHSA.org. State laws: issues. Seat Belts. Retrieved November 29, 2019.</ref> Seat belt use is also mandatory in [[Washington, D.C.]], the national capital, and the five inhabited [[Territories of the United States|U.S. territories]].<ref name="seat_belt1"/>

===Intercity bus===

[[Greyhound Lines]] is the largest [[Intercity bus service|intercity bus]] company<ref>{{cite web |url=https://www.greyhound.com/en/about/default.aspx |title=About Greyhound |publisher=Greyhound Lines |year=2015 |access-date=October 27, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20140214195235/http://www.greyhound.com/en/about/default.aspx |archive-date=February 14, 2014  }}</ref> in the United States, with routes in all parts of the [[contiguous United States|contiguous U.S.]] There are also many smaller regional bus companies, many of which use the terminal and booking facilities provided by Greyhound. Intercity bus is, in most cases, the least expensive way to travel long distances in the United States.<ref>{{Cite web |date=2011-12-15 |title=Intercity Buses are the Cost Effective Transportation Option |url=https://reason.org/commentary/intercity-buses-are-the-cost-effect/ |access-date=2024-06-04 |publisher=Reason Foundation |language=en-US}}</ref><ref>{{Cite journal |last1=Augustin |first1=Katrin |last2=Gerike |first2=Regine |last3=Martinez Sanchez |first3=Manuel Josue |last4=Ayala |first4=Carolina |date=2014-12-01 |title=Analysis of intercity bus markets on long distances in an established and a young market: The example of the U.S. and Germany |url=https://www.sciencedirect.com/science/article/pii/S0739885914000882 |journal=Research in Transportation Economics |series=Competition and Ownership in Land Passenger Transport (selected papers from the Thredbo 13 conference) |volume=48 |pages=245–254 |doi=10.1016/j.retrec.2014.09.047 |issn=0739-8859|url-access=subscription }}</ref>

===Congestion===
[[File:Los-Angeles-Airport-405-Freeway-Aerial-view-from-north-August-2014.jpg|thumb|Traffic on a typical [[Interstate Highway System|American freeway]] in [[Los Angeles]]]]
Traffic congestion, especially at rush hour, is often considered a problem in many of the country's larger cities. A 2009 study claimed that traffic congestion costs the United States almost $87.2 billion.<ref name=intelligent>{{cite web|title=Intelligent Transportation Systems – Congestion Initiative |url=https://www.its.dot.gov/research_archives/congestion/index.htm|url-status=dead |access-date=2021-11-01|publisher=[[U.S. Department of Transportation]]|archive-date=November 1, 2021|archive-url=https://web.archive.org/web/20211101065112/https://www.its.dot.gov/research_archives/congestion/index.htm}}</ref> The economic costs of traffic congestion have increased 63% over the past decade, and despite the declining traffic volumes caused by the economic downturn, Americans still waste more than {{convert|2.8|e9USgal|e6m3|abbr=off}} of fuel each year as a result of traffic congestion.<ref name=intelligent/>  Motorists also waste 4.2 billion hours annually, or one full workweek per traveler.<ref name=intelligent/><ref>{{cite web |url=http://mobility.tamu.edu/ums/media_information/press_release.stm |title=TTI: Urban Mobility Information: 2009 Annual Urban Mobility Report: Media Information: Press Release |access-date=February 9, 2010 |archive-url=https://web.archive.org/web/20100129104224/http://mobility.tamu.edu/ums/media_information/press_release.stm |archive-date=January 29, 2010 |url-status=dead}}</ref> Moreover, it is estimated that drivers are wasting 6.9 billion hours per year or about 42 hours per driver in traffic congestion as a result of aging infrastructure and poor road conditions.<ref name="Lyle">{{cite web|last1=Lyle |first1=Josh|title=Washington roads among worst in nation |url=http://www.king5.com/traffic/traffic-news/washington-roads-among-worst-in-nation/426746861|publisher=KING |access-date=April 1, 2017|archive-date=April 1, 2017 |archive-url=https://web.archive.org/web/20170401185812/http://www.king5.com/traffic/traffic-news/washington-roads-among-worst-in-nation/426746861|url-status=dead}}</ref>

The United States continues to follow a method of attempting to resolve congestion by widening roadways. From 1993 to 2017, the nation's largest 100 urbanized areas added 42% more freeway lane milage, despite population growing by only 32%. However, this policy of widening roadways resulted in a 144% increase in congestion, due to the concept of [[induced demand]].<ref>{{cite web | title=The Congestion Con | url=https://t4america.org/wp-content/uploads/2020/03/Congestion-Report-2020-FINAL.pdf | publisher=Transportation for America | access-date=June 27, 2022}}</ref>

===Cargo===
{{See also|Trucking industry in the United States}}
[[File:Orgill distribution truck.jpg|right|thumb|250px|[[Orgill (company)|Orgill]] distribution truck and trailer in [[Nevada]]]]
The trucking industry (also referred to as the transportation or logistics industry) involves the transport and distribution of commercial and industrial goods using [[commercial motor vehicles]] (CMV). In this case, CMVs are most often [[truck]]s; usually [[semi truck]]s, [[box truck]]s, or [[dump truck]]s. A [[truck driver]] (commonly referred to as a "trucker") is a person who earns a living as the driver of a CMV.

The trucking industry provides an essential service to the [[Economy of the United States|American economy]] by transporting large quantities of [[raw material]]s, [[Work in process|works in process]], and [[finished good]]s over land—typically from manufacturing plants to retail distribution centers. Trucks are also important to the construction industry, as dump trucks and portable [[concrete mixers]] are necessary to move the large amounts of rocks, dirt, concrete, and other construction material. Trucks in America are responsible for the majority of [[freight]] movement over land, and are vital tools in the manufacturing, transportation, and warehousing industries.

Large trucks and buses require a [[commercial driver's license]] (CDL) to operate. Obtaining a CDL requires extra education and training dealing with the special knowledge requirements and handling characteristics of such a large vehicle. Drivers of CMVs must adhere to the [[hours of service]], which are regulations governing the driving hours of commercial drivers. These, and all other rules regarding the safety of interstate commercial driving, are issued by the [[Federal Motor Carrier Safety Administration]] (FMCSA). The FMCSA is also a division of the [[United States Department of Transportation]] (USDOT), which governs all transportation-related industries such as trucking, [[Ship transport|shipping]], [[Rail transport in the United States|railroads]], and [[List of airlines#North America|airlines]]. Some other issues are handled by another branch of the USDOT, the [[Federal Highway Administration]] (FHWA).

Developments in technology, such as computers, [[satellite communication]], and the internet, have contributed to many improvements within the industry. These developments have increased the [[productivity]] of company operations, saved the time and effort of drivers, and provided new, more accessible forms of entertainment to men and women who often spend long periods of time away from home. In 2006, the [[U.S. Environmental Protection Agency]] implemented revised [[emission standards]] for diesel trucks (reducing [[airborne pollutants]] emitted by diesel engines) which promises to improve air quality and public health.

===Roadway links with adjacent countries and non-contiguous parts of the United States===

''Within the United States:''

*[[Transportation in Alaska|Alaska]] – Yes, via [[Canada]] and the [[Alaska Marine Highway]] in [[Washington (state)|Washington]]
*[[Transportation in Hawaii|Hawaii]] – No.
*[[Transportation in American Samoa|American Samoa]] – No.
*[[Transportation in Guam|Guam]] – No.
*[[Transportation in the Northern Mariana Islands|Northern Mariana Islands]] – No.
*[[Transportation in Puerto Rico|Puerto Rico]] – No.
*[[Transportation in the United States Virgin Islands|U.S. Virgin Islands]] – No.

''With adjacent countries:''

*[[Transportation in Canada|Canada]] – Yes.
*[[Transportation in Mexico|Mexico]] – Yes.
*[[Transportation in Russia|Russia]] – No, but proposed via [[Bering Strait crossing]]
*[[Transportation in Cuba|Cuba]] – No. Since the [[United States embargo against Cuba|American embargo]] against [[Cuba]], [[Train ferry|car ferry]] service from [[Florida]] and [[New Orleans]] to [[Havana]] ceased in 1962.<ref name=CubaFerry>Luxner, Larry. "Shipping firm sees potential gold mine in Florida-Cuba passenger ferry service." CubaNews Sept. 2009: 1+. General Reference Center Gold. Web. February 9, 2010.</ref>
*[[Transportation in the Bahamas|Bahamas]] – No, but ferries travel to the Bahamas

===Traffic codes===
{{Main|Traffic code in the United States}}
Each state has its own [[traffic code]], although most of the rules of the road are similar for the purpose of uniformity, given that all states grant reciprocal driving privileges (and [[Traffic Violations Reciprocity|penalties]]) to each other's licensed drivers.

==Air transportation==
{{Main|Aviation in the United States}}
{{Further|List of airlines of the United States|List of airports in the United States}}
[[File:N736AT (30164319228).jpg|thumb|A [[Boeing 777]] from the United States landing at [[London Heathrow Airport]]. [[Air travel]] is the most popular means of long-distance passenger travel in the United States.]]
[[File:Atlanta Airport Aerial Angle (31435634003) (2) (cropped).jpg|thumb|[[Hartsfield–Jackson Atlanta International Airport]] in the [[Atlanta metropolitan area]], the world's busiest airport by [[List of busiest airports by passenger traffic|passenger traffic]] with 108.1 million passengers annually in 2024<ref>{{cite web|url=https://www.cnn.com/travel/article/worlds-busiest-airports-2021/index.html|title=This US airport has reclaimed its title as the world's busiest|publisher=CNN |first=Marnie|last=Hunter|date=April 11, 2022}}</ref>]]
The United States has advanced air transportation infrastructure which utilizes approximately 5,000 paved runways. In terms of passenger traffic, 17 of the world's 30 busiest airports in 2004 were in the United States, including the world's busiest, [[Hartsfield-Jackson Atlanta International Airport]]. In terms of cargo, in the same year, 12 of the world's 30 busiest airports were in the United States, including the world's busiest, [[Memphis International Airport]].<ref>{{cite news |url=http://www.commercialappeal.com/news/2009/feb/04/memphis-maintains-hold-largest-cargo-airport-weigh/ |title=Memphis maintains hold as largest cargo airport by weight |access-date=February 4, 2009 |date=February 4, 2009 |work=Commercial Appeal |archive-date=February 8, 2009 |archive-url=https://web.archive.org/web/20090208125630/http://www.commercialappeal.com/news/2009/feb/04/memphis-maintains-hold-largest-cargo-airport-weigh/ |url-status=live}}</ref> Private aircraft are also used for medical emergencies, government agencies, large businesses, and individuals, see [[general aviation]].

There is no single national [[flag airline]]; [[passenger airline]]s in the United States have always been privately owned. There are over 200 domestic passenger and cargo [[airline]]s and a number of international carriers. The major international carriers of the United States are [[Delta Air Lines]], [[American Airlines]], and [[United Airlines]]. [[Low-cost carrier]] [[Southwest Airlines]] operates few international routes, but has grown its domestic operations to a size comparable to the major international carriers.  There is currently no government regulation of ticket pricing, although the [[Federal government of the United States|federal government]] retains jurisdiction over aircraft safety, pilot training, and accident investigations (through the [[Federal Aviation Administration]] and the [[National Transportation Safety Board]]). The [[Transportation Security Administration]] provides security at airports.

==Rail==
{{Main|Rail transportation in the United States}}

===Passenger===
[[File:North America Passenger Trains.png|thumb|{{center|Passenger trains in [[North America]]}}]]
[[File:Grand Central Board.jpg|thumb|[[Grand Central Terminal]] in [[New York City]], the second-busiest train station by passenger traffic in [[North America]] after [[New York Penn Station]], also in New York City]]
Passenger [[trains]] were the dominant [[mode of transportation]] until the mid-twentieth century. The introduction of jet airplanes on major U.S. routes and the completion of the Interstate Highway System accelerated a decline in intercity rail passenger demand during the 1960s, resulting in the sharp curtailment of passenger service by private railroads. This led to the creation of National Railroad Passenger Corporation, now called [[Amtrak]], by the [[Federal government of the United States|U.S. federal government]] in 1971 to maintain limited intercity rail passenger service in most parts of the country. Amtrak serves most major cities but, outside of the [[Northeastern United States|Northeast]], [[California]], and [[Illinois]], often by only a few trains per day. Amtrak does not serve several major destinations, including [[Las Vegas]], and [[Phoenix, Arizona]]. Frequent service is available in regional corridors between certain major cities, particularly the [[Northeast Corridor]] between [[Washington, D.C.]], [[Philadelphia]], [[New York City]] and [[Boston]], between [[New York City]] and [[Albany, New York|Albany]], around [[Chicago]], and in parts of California and the [[Pacific Northwest]].

Private intercity rail ended in the United States in 1983 with the discontinuation of the [[Rio Grande Zephyr]], until [[Brightline]] started in South Florida in 2018. The state-owned [[Alaska Railroad]] is the only other intercity passenger railroad still operating. It has only [[train ferry|rail ferry]] connections with other railroads.

====Rapid transit====
{{See also|High-speed rail in the United States|Commuter rail in North America}}
There are 15 heavy rail [[rapid transit]] systems in the United States. The [[New York City Subway]] is the largest rapid transit system in the world by number of stations.

===Cargo===
The United States makes extensive use of its rail system for [[freight train|freight]]. According to the [[Association of American Railroads]], "U.S. freight railroads are the world's busiest, moving more freight than any rail system in any other country. In fact, U.S. railroads move more than four times as much freight as do all of Western [[Rail transport in Europe|Europe]]'s freight railroads combined."

Nearly all railroad corridors not including local transit rail systems are owned by private companies that provide freight service. [[Amtrak]] pays these companies for the right to use the tracks for passenger service. There are approximately {{cvt|150,000|mi}} of [[List of United States railroads|mainline track in the United States]]—the world's longest national railroad network.
[[File:Amtrak P42DC 164 through Orange, Virginia.jpg|thumb|Amtrak P42DC 164 through Orange, [[Virginia]]]]
Rail freight has a major national bottleneck in Chicago and the Midwest, representing approximately one-third of the nation's freight trains pass through the region,<ref name="heartland">{{cite web|url=http://www.entrepreneur.com/tradejournals/article/171140041.html|title=The heartland fast-freight rail system.|author=Bucklew, Keith J.|date=Fall 2007|publisher=Entrepreneur.com|access-date=June 18, 2009|archive-date=January 7, 2009|archive-url=https://web.archive.org/web/20090107103746/http://www.entrepreneur.com/tradejournals/article/171140041.html|url-status=live}}</ref> which is the subject of an ongoing $4.6 billion infrastructure improvement project which started in 2003.

===Railway links with adjacent countries===
*[[Transportation in Canada|Canada]] – [[Amtrak]] connections run daily between [[New York City]] and [[Montreal|Montreal, Quebec]], [[Toronto|Toronto, Ontario]], and [[Seattle]] and [[Vancouver|Vancouver, British Columbia]]. [[Alaska]] is currently rail-accessible by [[train ferry]] from [[Bellingham, Washington]] and narrow gauge railroad from Whitehorse, Yukon Territory to Skagway. A proposed link to the [[contiguous United States]] would link Alaska and Canada via the [[Yukon]] and [[British Columbia]].<ref>{{cite web |url=http://www.alaskacanadarail.org |title=Alaska Canada Rail Link Phase 1 |publisher=Government of Yukon |date=October 1, 2013 |access-date=October 27, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20130117104414/http://www.alaskacanadarail.org/ |archive-date=January 17, 2013  }}</ref> The [[Canadian National Railway]] system includes the former [[Illinois Central]] route from [[Chicago]] via [[Memphis, Tennessee|Memphis]] to [[New Orleans]].
*[[Transportation in Mexico|Mexico]] – Several private firms run touristic trains from near [[El Paso, Texas]], through [[Chihuahua, Chihuahua]] and the [[Copper Canyon]] to [[El Fuerte, Sinaloa]]. Such trains also run from [[Nogales, Sonora]], but no U.S. passenger trains run near [[Nogales, Arizona]], on the other side of the border. Another touristic train runs occasional trains between [[Campo, California]], and [[Tecate, Baja California]].

With few exceptions, the [[rail gauge]] is [[standard gauge]] {{RailGauge|ussg}}. The [[White Pass and Yukon Route]] from [[Skagway, Alaska|Skagway]], [[Alaska]] to [[Whitehorse, Yukon|Whitehorse]], [[Yukon]] by way of [[Bennett, British Columbia|Bennett]], [[British Columbia]] is {{RailGauge|3ft}} gauge.

==Mass transit==
{{Main|Public transportation in the United States|List of bus transit systems in the United States}}
[[File:Thirty St Station.jpg|thumb|[[30th Street Station]] in [[Philadelphia]]]]
[[File:METRORail 5.jpg|thumb|[[METRORail]] on Main Street in [[Downtown Houston]]]]
The miles traveled by passenger vehicles in the United States fell by 3.6% in 2008, while the number of trips taken on mass transit increased by 4.0%. At least part of the drop in urban driving can be explained by the 4% increase in the use of public transportation.<ref>{{cite web |url=http://apps1.eere.energy.gov/news/news_detail.cfm/news_id=12283 |title=U.S. Transit Use Up, Driving Down in 2008 |publisher=US Department of Energy, EERE News Archives and Events |date=March 11, 2009 |access-date=October 27, 2015 |archive-date=May 4, 2009 |archive-url=https://web.archive.org/web/20090504112756/http://apps1.eere.energy.gov/news/news_detail.cfm/news_id=12283 |url-status=live}}</ref>

Most medium-sized cities have some sort of local public transportation, usually a network of fixed bus routes. Among larger cities many of the older cities also have [[rapid transit|metro]] rail systems (also known as [[heavy rail]] in the United States) and/or extensive light rail systems, while the newer cities found in the [[Sun Belt]] either have modest [[light rail]] systems or have no intracity rail at all.

===Legislation===
On June 26, 2008, the House passed the Saving Energy Through Public Transportation Act (H.R. 6052),<ref name="issuesnpspeaker">{{cite web|url=http://speaker.gov/issues?id=0031#13|title=Speaker Nancy Pelosi|author=Nancy Pelosi|access-date=June 18, 2009|url-status=dead|archive-url=https://web.archive.org/web/20081002112628/http://speaker.gov/issues?id=0031#13|archive-date=October 2, 2008}}</ref> which gives grants to |mass transit authorities to lower [[fare]]s for [[commuter]]s [[wikt:pinched|pinched]] at the pump{{clarify|What does pinched at the pump mean?|date=February 2023}} and expand transit services. The bill also:

*Requires that all Federal agencies offer their employees transit pass transportation fringe benefits.  Federal agencies within the National Capital Region have successful transit pass benefits programs.
*Increases the federal cost-share of grants for construction of additional parking facilities at the end of subway lines from 80 to 100% to cover an increase in the number of people taking mass transit.
*Creates a pilot program for [[vanpool]] demonstration projects in urban and rural areas.
*Increases federal help for local governments to purchase alternative fuel buses, locomotives, and ferries from 90 to 100%.

==Water transportation==
[[File:Mississippi tugboat.jpg|thumb|A tugboat on the [[Mississippi River]] seen from [[St. Louis]]]]
[[Water transport]] is largely used for freight. Fishing and pleasure boats are numerous, and passenger service connects many of the nation's islands and remote coastal areas, crosses lakes, rivers, and harbors, and provides alternative access to [[Alaska]] which bypasses [[Canada]]. Several major [[seaport]]s in the United States include [[New York City]] on the east coast, [[New Orleans]] and [[Houston]] on the gulf coast, and [[Los Angeles]] on the west coast.<ref>[http://www.infoplease.com/ipa/A0104779.html Rank Order – Seaports] {{Webarchive|url=https://web.archive.org/web/20070527190727/http://www.infoplease.com/ipa/A0104779.html |date=May 27, 2007 }}. Infoplease.com</ref> The interior of the U.S. also has major [[Channel (geography)|shipping channels]], via the [[Great Lakes Waterway]], [[St. Lawrence Seaway]] and the [[Mississippi River System]]. Freight on the Mississippi River system is carried on [[barge]]s pushed by approximately 8000 "[[towboat]]s" and largely consists of bulk goods, such as petrochemicals, grain and cement.<ref name=MissR>{{cite web|url=http://www.gatewayno.com/history/Mississippi.html|title=Mississippi River |website=Gatewayno.com|access-date=October 14, 2017|archive-date=May 30, 2010|archive-url=https://web.archive.org/web/20100530081538/http://www.gatewayno.com/history/Mississippi.html|url-status=live}}</ref>

Many U.S. ports are served by [[cruise ships]]. Popular destinations include the [[Caribbean]], the [[Mexican Riviera]], [[Hawaii]] and the [[Inside Passage]] to Alaska.<ref>"Cruise industry predicts smooth sailing." Colorado Springs Business Journal [CO] April 27, 2007. General Reference Center Gold. Web. February 9, 2010.</ref> [[ferry|Automobile ferries]] operate in many locations where bridges are impractical and in congested metropolitan areas, including [[New York City]] and [[San Francisco Bay]].<ref>"Officials eye ferries to help ease congestion: Water Transit Agency hopes to build eight new terminals to go along with the six already in use." Contra Costa Times [Walnut Creek, CA] June 26, 2006. General Reference Center Gold. Web. February 9, 2010.</ref> Ferries also operate in [[Sound (geography)|Sounds]] that have populated areas surrounding it, such as [[Puget Sound]]. [[Washington State Ferries]] operates the ferries in Puget Sound and has the second largest ferry fleet in the world. Washington State ferries even offer ferries from [[Anacortes, Washington]] to [[Sidney, British Columbia]].

===Waterways===
{{further|Inland waterways of the United States}}
The United States has {{convert|25482|mi|km}} of [[navigable]] inland channels ([[river]]s and [[canal]]s), exclusive of the [[Great Lakes]]. Out of this {{convert|12006|mi|km}} is used in commerce. About {{convert|15000|mi|km}} of the [[Mississippi River System]] are presently navigable, although not all is used for commerce.<ref name=MissR/> The [[Saint Lawrence Seaway]] of {{convert|2342|mi|km}}, including the [[Saint Lawrence River]] of {{convert|1900|mi|km}}, is shared with Canada.<ref name="ciafactbook">{{cite web|url=https://www.cia.gov/the-world-factbook/countries/united-states/|title=CIA&nbsp;— THe World Factbook&nbsp;— United States|access-date=June 14, 2009|archive-date=March 21, 2021|archive-url=https://web.archive.org/web/20210321202516/https://www.cia.gov/the-world-factbook/countries/united-states/|url-status=live}}</ref>

===Ports and harbors===
{{Main|List of ports in the United States}}
United States ports and harbors include:
{{Col-begin}}
{{Col-break}}
*[[Anchorage, Alaska]]
*[[Baltimore|Baltimore, Maryland]]
*[[Boston|Boston, Massachusetts]]
*[[Charleston, South Carolina]]
*[[Chicago|Chicago, Illinois]]
*[[Christiansted, U.S. Virgin Islands]]
*[[Detroit|Detroit, Michigan]]
*[[Erie, Pennsylvania]]
*[[Gulfport, Mississippi]]
*[[Hampton Roads|Hampton Roads, Virginia]]
*[[Honolulu|Honolulu, Hawaii]]
*[[Houston|Houston, Texas]]
{{Col-break}}
*[[Jacksonville, Florida]]
*[[Long Beach, California]]
*[[Los Angeles|Los Angeles, California]]
*[[Miami|Miami, Florida]]
*[[Mobile, Alabama]]
*[[New Orleans|New Orleans, Louisiana]]
*[[Newark, New Jersey|Newark]]-[[New York City]]
*[[Pago Pago|Pago Pago, American Samoa]]
*[[Philadelphia|Philadelphia, Pennsylvania]]
*[[Pittsburgh|Pittsburgh, Pennsylvania]]
*[[Port Canaveral, Florida]]
{{Col-break}}
*[[Portland, Oregon]]
*[[Providence, Rhode Island]]
*[[Oakland, California]]
*[[Sacramento, California]]
*[[Saipan|Saipan, Northern Mariana Islands]]
*[[San Diego|San Diego, California]]
*[[San Juan, Puerto Rico]]
*[[Savannah, Georgia]]
*[[Seattle|Seattle, Washington]]
*[[Tacoma, Washington]]
*[[Tampa, Florida]]
*[[Toledo, Ohio]]
*[[Valdez, Alaska]]
{{Col-end}}

===Merchant marine===
{{Further|List of longest rivers of the United States (by main stem)|United States Merchant Marine}}
[[File:Houston Ship Channel Barbours Cut.jpg|thumb|The [[Barbours Cut Terminal]] at the [[Port of Houston]], one of the world's largest ports]]
Most U.S. exports and imports are on foreign ships.  The 1920 [[Merchant Marine Act of 1920|Jones Act]] bars foreign ships from trade within the United States, thus creating a domestic "Jones Act fleet".  Deck officers and ship's engineers of U.S.-flagged ships are usually trained at one of the established maritime academies.<ref>Maritime academies include the federal [[United States Merchant Marine Academy]] in [[Kings Point, New York]], [[Maine Maritime Academy]] in [[Castine, Maine|Castine]], [[Massachusetts Maritime Academy]] in [[Buzzards Bay, Massachusetts|Buzzard's Bay]], [[State University of New York Maritime College]] in [[the Bronx]], [[Texas A&M University at Galveston|Texas Maritime Academy]] in [[Galveston, Texas|Galveston]], [[California Maritime Academy]] in [[Vallejo, California|Vallejo]], and [[Northwestern Michigan College|Great Lakes Maritime Academy]] in [[Traverse City, Michigan]].</ref>

==Military==
The [[Military of the United States|federal military]] has a dedicated system of bases with runways, aircraft, watercraft, conventional cars and trucks, and armored and special-purpose vehicles.  During times of war, it may commandeer private infrastructure and vehicles as authorized by [[United States Congress|Congress]] and the [[President of the United States|President]].<ref>{{cite web|title=A Guide to Emergency Powers and Their Use |publisher=Brennan Center for Justice |url=https://www.brennancenter.org/our-work/research-reports/guide-emergency-powers-and-their-use|access-date=2020-10-02 |archive-date=October 20, 2020|archive-url=https://web.archive.org/web/20201020003647/https://www.brennancenter.org/our-work/research-reports/guide-emergency-powers-and-their-use|url-status=live}}</ref>

{{See also|Humvee}}

[[File:AM General HMMWV M998 (9205324520).jpg|thumb|a [[Humvee]] military vehicle]]

==Pipeline statistics==
* [[Petroleum]] products: 224,620&nbsp;km
* Natural gas: 548,665&nbsp;km (2006)<ref name="ciafactbook" />

==Policy==
{{Main|Transportation policy of the United States}}
As the population of the world increases, cities grow in size and population – according to the United Nations, 55% of the world's population live in cities, and by 2050 this number is expected to rise to 68%.<ref>{{cite news |last=Meredith |first=Sam |date=May 17, 2018 |title=Two-thirds of global population will live in cities by 2050, UN says |url=https://www.cnbc.com/2018/05/17/two-thirds-of-global-population-will-live-in-cities-by-2050-un-says.html |publisher=CNBC |access-date=November 20, 2018 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112041309/https://www.cnbc.com/2018/05/17/two-thirds-of-global-population-will-live-in-cities-by-2050-un-says.html |url-status=live}}</ref> Public transportation policy must evolve to meet the changing priorities of the urban world.<ref>{{cite journal |title=The evolution of urban mobility: The interplay of academic and policy perspectives |last=Jones |first=Peter |date=July 2014 |journal=Iatss Research |volume=38 |pages=7–13 |doi=10.1016/j.iatssr.2014.06.001 |doi-access=free }}</ref> The institution of policy enforces order in transportation, which is by nature chaotic as people attempt to travel from one place to another as fast as possible. This policy helps to reduce accidents and save lives.

===Pedestrian===
A key component of a suitable urban environment is support for pedestrian traffic, including people on foot as well as human propelled vehicles like bikes, skateboards, and scooters. Pedestrian policy is implemented at the state level, but consistent across states is the fact that the pedestrian has the right-of-way. If someone on foot is crossing the street, legally or illegally, any vehicular traffic is required to stop—under no circumstance does a driver have a right to hit a pedestrian. The exact details with respect to when a vehicle has to stop differ between the states, some requiring that all vehicles at an intersection yield to a pedestrian, while others requiring only those vehicles perpendicular to the motion of the crossing to stop.<ref>{{cite web |url=http://www.ncsl.org/research/transportation/pedestrian-crossing-50-state-summary.aspx |title=Pedestrian Crossing: 50 States Summary |author=<!--Not stated--> |date=May 23, 2018 |publisher=National Conference of State Legislatures |access-date=November 20, 2018 |archive-date=November 26, 2021 |archive-url=https://web.archive.org/web/20211126124619/https://www.ncslcommunities.org/engage/idp/login?app=0spf4000000PBE6&RelayState=0711206c-3f46-407a-81ca-07e16a2f8b2e&binding=HttpPost&inresponseto=_b73fc7b8-261a-4ff4-98c5-68a7ab83c02d |url-status=dead }}</ref> California requires all vehicles at an intersection to yield to a pedestrian walking in any direction.

There are also rules for pedestrian conduct. Though they have the right-of-way, pedestrians are not permitted to leave a curb into a crosswalk close enough to a vehicle to “constitute hazard.”<ref>National Conference of State Legislatures, 2018</ref> Pedestrians must also yield to mass transit like light-rail cars and trains, as these forms of transportation operate on a schedule and are often moving too quickly to yield to a pedestrian. Pedestrians are also not permitted to delay traffic more than necessary while in a crosswalk. When not using a crosswalk, pedestrians must yield their right-of-way to vehicles who are close enough to constitute hazard. One of the issues with this kind of policy is how vague it is. A pedestrian is expected to determine on the fly what “constitutes hazard,” which can create dangerous situations leading to pedestrian injury or even death. As technology continues to advance, embedded technology like sensors and computer chips in vehicles should be able to process data very quickly and thus prevent collisions, as discussed in the Internet section found below.

===Complete Street===
A complete street is a roadway that is safe for people of any ability or age utilizing any form of transportation.<ref>{{cite web |url=http://smartgrowthamerica.us/documents/cs/resources/cs-ite-may08.pdf |title=Complete Streets: We Can Get There from Here |last=LaPlante |first=John |publisher=Open Publishing |date=May 2008 |website=Smart Growth America |access-date=November 20, 2018 |archive-url=https://web.archive.org/web/20181129142348/http://smartgrowthamerica.us/documents/cs/resources/cs-ite-may08.pdf |archive-date=November 29, 2018 |url-status=live}}</ref> The concept revolves around the fact that streets are communal spaces, so anyone has a right to access them. In order to ensure universal safety, however, policy exists to ensure that these complete streets are maintained and utilized properly.
* Funding policies refer to the process with which state funds are allocated to the creation of pedestrian areas, bike lanes, and street markings.
* Planning policies refer to the process by which a street is expanded to include support for human powered transportation and how * this expansion fits into the urban planning as a whole.
* Engineering and design policies refer to the implementation of a complete street, including how to differentiate between bike lanes and car lanes.
* Maintenance policies refer to the process with which state funds are allocated to street maintenance to ensure that they remain safe places of travel.
* Use policies refer to the proper use of a complete street to allow efficient transportation for all.<ref>{{cite web |url=https://www.aarp.org/content/dam/aarp/livable-communities/old-learn/transportation/public-policies-for-pedestrian-and-bicyclist-safety.pdf |title=Public Policies for Pedestrian and Bicyclist Safety and Mobility |author=<!--Not stated--> |date=August 2010 |publisher=U.S. Department of Transportation |access-date=November 20, 2018 |archive-date=April 12, 2019 |archive-url=https://web.archive.org/web/20190412095253/https://www.aarp.org/content/dam/aarp/livable-communities/old-learn/transportation/public-policies-for-pedestrian-and-bicyclist-safety.pdf |url-status=live }}</ref>

Other supporting policies indirectly related to complete streets include parking policies and vehicle restrictions. Complete streets are an important development for urban transportation because they equally support all forms of transportation, enforce safety, and ensure that everyone can navigate the busy city streets to arrive at their destination as fast as possible.

===Traffic flow===
In order to ensure that [[traffic flow]] is uniformly dispersed across roadways and does not interfere with existing pedestrian and public transportation infrastructure, traffic flow policy is put in place in order to get everyone to their destination in the most efficient way possible. Traffic flow policy includes everything from how spaced out two cars should be on a highway to which cars have priority at stop signs and street lights to the proper use of bus, taxi, and carpool lanes.

=== Parking lots ===
{{Further|Parking mandates}}
Parking policy has a strong impact on the transportation mode. Efforts to reduce the amount of space dedicated to parking are diminishing the dependence on cars, encouraging walking, biking, public transit, lowering the cost of housing and increase the amount of housing units that can be built in the city territory. Such efforts has been taken in different cities in [[California]]<ref>{{cite web |title=To Tackle Climate Change, Cities Need to Rethink Parking |url=https://www.itdp.org/2022/09/20/to-tackle-climate-change-cities-need-to-rethink-parking/ |publisher=Institute for Transportation & Development Policy |date=September 20, 2022 |access-date=7 November 2023}}</ref> and in September 2023 the state abolished the requirement of minimum parking space "within a half-mile of major public transit stops".<ref>{{cite news |last1=KHOURI |first1=ANDREW |title=California bans mandated parking near transit to fight high housing prices, climate change |url=https://www.latimes.com/california/story/2022-09-23/newsom-bill-banning-parking-requirement-transit-housing-climate-change |access-date=27 November 2023 |agency=Los Angeles Times |date=23 September 2023}}</ref> From 2017 more than 200 towns and cities in the USA abolished or changed the requirement for parking minimum.<ref>{{cite web |last1=Franzen |first1=Carl |title=The End of Parking Minimums |url=https://www.lyft.com/blog/posts/the-end-of-parking-minimums |publisher=Parking Reform Network |access-date=27 November 2023}}</ref> Those include [[Portland, Oregon|Portland]], [[Minneapolis]], [[Austin, Texas|Austin]]. As of 2 November 2023, Austin (Texas) is the biggest city in the USA that did it.<ref>{{cite news |last1=FECHTER |first1=JOSHUA |title=To fight climate change and housing shortage, Austin becomes largest U.S. city to drop parking-spot requirements |url=https://www.texastribune.org/2023/11/02/austin-minimum-parking-requirements-housing-shortage/ |access-date=7 November 2023 |agency=Texas tribune |date=2 November 2023}}</ref> Some cities including [[Nashville, Tennessee|Nashville]], begun to impose parking maximum.<ref>{{cite news |last1=Meyersohn |first1=Nathaniel |title=This little-known rule shapes parking in America. Cities are reversing it |url=https://edition.cnn.com/2023/05/20/business/parking-minimums-cars-transportation-urban-planning/index.html |access-date=27 November 2023 |agency=CNN |date=21 May 2023}}</ref>

==Funding==
<!-- "Major Investment Study" redirects to this section -->
{{Update|reauthorization|date=May 2010}}
[[File:Transportation GDP.png|800px|center|Federal, State, and Local spending on transportation as a percent of GDP]]
Federal, state, and local tax revenues support upkeep of most roads, which are generally free to drivers. There are also some [[toll road]]s and [[toll bridge]]s.  Most other forms of transportation charge a fee for use as they are not given much, if any, tax support by Congress.

Government funding of transportation exists at many levels. Federal funding for highway, rail, bus, water, air, and other forms of transportation is allocated by Congress for several years at a time.  The current authorization bill is the [[Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users]] (SAFETEA-LU), which runs from 2005 to 2009. A Congressionally chartered committee is considering future funding issues.<ref name="nstifc">{{cite web |url=http://financecommission.dot.gov/ |title=National Surface Transportation Infrastructure Financing Commission |publisher=US Department of Transportation |date=February 26, 2009 |access-date=June 18, 2009 |archive-date=June 11, 2009 |archive-url=https://web.archive.org/web/20090611063351/http://financecommission.dot.gov/ |url-status=dead }}</ref>{{update inline|date=December 2018}}

Though [[earmark (finance)|earmarks]] are often made for specific projects, the allocation of most federal dollars is controlled by [[metropolitan planning organization]]s (MPOs) and state governments.  Usually "matching" funds are required from local sources.  All projects have a sponsoring agency that will receive the funding from the various federal and local sources, and be responsible for implementing the project directly or through contracts.  Large projects require a Major Investment Study' and both a draft and final [[Environmental impact assessment|Environmental Impact Review]]. A patchwork of federal laws and accounts govern the allocation of federal transportation dollars, most of which is reserved for capital projects, not operating expenses.  Some roads are federally designated as part of the [[National Highway System (United States)|National Highway System]] and get preferential funding as a result, but there are few [[List of United States federally maintained roads|federally maintained roads]] outside of [[Washington, D.C.]], and national parks.

State governments are sovereign entities which use their powers of taxation both to match federal grants, and provide for local transportation needs.  Different states have different systems for dividing responsibility for funding and maintaining road and transit networks between the state department of transportation, counties, municipalities, and other entities. Cities or counties are typically responsible for local roads, financed with block grants and local property taxes, and the state is responsible for major roads that receive state and federal designations.  Many mass transit agencies are quasi-independent and subsidized branches of a state, county, or city government.

==Economic impact==
According to the [[U.S. Department of Transportation]] (DOT): "Transportation's vital importance to the U.S. economy is underscored by the fact that more than $1 out of every $10 produced in the U.S. [[gross domestic product]] is related to transportation activity. This includes all aspects of transportation, including the movement of goods and the purchase of all transportation-related products and services as well as the movement of people".<ref>{{cite web
|url=http://www.bts.gov/publications/freight_in_america/html/nations_freight.html
|title=The Nation's Freight
|access-date=February 8, 2008
|work=Freight in America
|publisher=U.S. Department of Transportation&nbsp;— Bureau of Transportation Statistics
|archive-date=March 28, 2008
|archive-url=https://web.archive.org/web/20080328001250/http://www.bts.gov/publications/freight_in_america/html/nations_freight.html
|url-status=dead
}}</ref> Employment in the transportation and material moving industry accounted for 7.4% of all employment, and was the 5th largest employment group in the United States.<ref>{{cite web
|url=http://www.bls.gov/oes/2005/may/major.pdf
|title=Employment and Wages by Major Occupational Group and Industry
|access-date=February 29, 2008
|publisher=Bureau of Labor Statistics
|archive-date=April 9, 2008
|archive-url=https://web.archive.org/web/20080409061109/http://www.bls.gov/oes/2005/may/major.pdf
|url-status=live
}}</ref>

The United States invests 0.6% of its GDP on transportation annually.<ref>{{cite news | first=Jay | last=Bookman | title=Opinion:Toll roads, taxes and why voters distrust leaders | url=http://blogs.ajc.com/jay-bookman-blog/2010/10/08/tolls-a-result-of-avoiding-the-real-issue/?cxntfid=blogs_jay_bookman_blog | newspaper=Atlanta Journal-Constitution | location=Atlanta, Georgia | pages=A18 | date=October 8, 2010 | access-date=October 17, 2010 | archive-url=https://web.archive.org/web/20101011233411/http://blogs.ajc.com/jay-bookman-blog/2010/10/08/tolls-a-result-of-avoiding-the-real-issue/?cxntfid=blogs_jay_bookman_blog | archive-date=October 11, 2010 | url-status=dead }}</ref><!---from a transportation study. If found, that should be substituted--->

==Environmental impacts==
[[File:Corn vs Ethanol production.webp|thumb|300px|Corn vs Ethanol production in the United States
{{legend|#FFD932|Total corn production ([[bushel]]s) (left)}}
{{legend|B51700|Corn used for [[Ethanol fuel]] (bushels) (left)}}
{{legend-line|#313131 solid 3px|Percent of corn used for Ethanol (right)}}
]]
Two-thirds of U.S. [[oil consumption]] is due to the transportation sector.<ref name=btstable4-3>{{cite web
  |url=http://www.bts.gov/publications/national_transportation_statistics/html/table_04_03.html
  |title=Domestic Demand for Refined Petroleum Products by Sector
  |publisher=U.S. [[Bureau of Transportation Statistics]]
  |access-date=December 20, 2007
  |archive-url=https://web.archive.org/web/20070929124343/http://www.bts.gov/publications/national_transportation_statistics/html/table_04_03.html
  |archive-date=September 29, 2007
  |url-status=dead
  }}</ref><ref>{{cite web|url=https://www.washingtonpost.com/wp-dyn/articles/A17039-2004Jun4.html|title=After the Oil Runs Out|website=The Washington Post |access-date=October 14, 2017|archive-date=May 5, 2017|archive-url=https://web.archive.org/web/20170505145108/http://www.washingtonpost.com/wp-dyn/articles/A17039-2004Jun4.html|url-status=live}}</ref> The [[Energy Independence and Security Act of 2007]] has an impact on [[Energy policy of the United States|U.S. Energy Policy]].<ref name=EISA>{{cite web
|url = http://www.thomas.gov/cgi-bin/query/z?c110:H.R.6.ENR:
|title = Energy Independence and Security Act of 2007 (Enrolled as Agreed to or Passed by Both House and Senate)
|access-date = January 18, 2008
|archive-date = January 15, 2016
|archive-url = https://web.archive.org/web/20160115001453/http://www.thomas.gov/cgi-bin/query/z?c110%3AH.R.6.ENR%3A
|url-status = dead
}}</ref> The United States, an important export country for food stocks, converted 18% of its grain output to [[Ethanol fuel in the United States|ethanol]] in 2008. Across the United States, 25% of the whole corn crop went to ethanol in 2007.<ref name="25perc">{{cite magazine|url=http://www.time.com/time/business/article/0,8599,1684910,00.html?iid=sphere-inline-sidebar|archive-url=https://web.archive.org/web/20111027053654/http://www.time.com/time/business/article/0,8599,1684910,00.html?iid=sphere-inline-sidebar|url-status=dead|archive-date=October 27, 2011|title=After the Oil Crisis, a Food Crisis? |author= Kathleen Kingsbury|magazine=Time Magazine|access-date=April 28, 2008|date=November 16, 2007}}</ref> The percentage of corn going to biofuel is expected to go up.<ref>{{cite web|url=https://www.telegraph.co.uk/money/ |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/money/ |archive-date=January 12, 2022 |url-access=subscription |url-status=live|title=Money|date=February 16, 2016|access-date=October 14, 2017|website=The Daily Telegraph}}{{cbignore}}{{dead link|date=July 2021|bot=medic}}{{cbignore|bot=medic}}</ref><ref>{{cite web|url=https://maritimedocumentation.us |archive-url=https://ghostarchive.org/archive/20220112/https://maritimedocumentation.us/ |archive-date=January 12, 2022 |url-access=subscription |url-status=live|title=US Vessel Documentation Center|date=February 16, 2016|access-date=October 14, 2017|website=Maritimedocumentation.us}}</ref> In 2006, U.S. Senators introduced the [[BioFuels Security Act]], which would mandate the production of dual-fuel vehicles and the sale of [[E85]] ethanol fuel.<ref>Baltimore, Chris. [http://www.boston.com/news/nation/washington/articles/2007/01/05/new_us_congress_looks_to_boost_alternate_fuels/?p1=MEWell_Pos5 "New U.S. Congress looks to boost alternate fuels,"] {{Webarchive|url=https://web.archive.org/web/20080617023230/http://www.boston.com/news/nation/washington/articles/2007/01/05/new_us_congress_looks_to_boost_alternate_fuels/?p1=MEWell_Pos5 |date=June 17, 2008 }} ''[[The Boston Globe]]'', January 5, 2007. Retrieved on August 23, 2007</ref>

===Greenhouse gas emissions===
[[File:20250319 US greenhouse gas emissions by sector.svg |thumb |Greenhouse gas emissions in the U.S., arranged by economic sector.<ref name=EPAghg_20250319>{{cite web |title=Greenhouse Gas Inventory Data Explorer |url=https://cfpub.epa.gov/ghgdata/inventoryexplorer/index.html |publisher=U.S. Environmental Protection Agency |access-date=19 March 2025 |archive-url=https://web.archive.org/web/20250317060305/https://cfpub.epa.gov/ghgdata/inventoryexplorer/index.html#allsectors/allsectors/allgas/econsect/current |archive-date=17 March 2025 |url-status=dead}} (Select display options: 1. All sectors, 2. All sectors, 3. All gases, 4. Economic Sector, 5. Most recent year, 6. National)</ref> About 10% of the transportation-based emissions was emitted by air travel.<ref name=EPA2023/>]]
Burning [[fossil fuel]]s like gasoline and diesel releases carbon dioxide, a [[greenhouse gas]].<ref name=EPAcarbonPollution_20250319/> The buildup of greenhouse gases causes the Earth’s lower atmosphere to warm, [[climate change|changing Earth's climate]].<ref name=EPAcarbonPollution_20250319/> From 1990 to 2022 in the U.S., emissions from transportation increased more in absolute terms than any other sector.<ref name=EPAcarbonPollution_20250319>{{cite web |title=Carbon Pollution from Transportation / Transportation and Climate Change |url=https://www.epa.gov/transportation-air-pollution-and-climate-change/carbon-pollution-transportation |publisher=U.S. Environmental Protection Agency |access-date=19 March 2025 |archive-url=https://web.archive.org/web/20250317084657/https://www.epa.gov/transportation-air-pollution-and-climate-change/carbon-pollution-transportation |archive-date=17 March 2025 |url-status=live}}</ref>

Transportation led U.S. [[greenhouse gas emissions]] in 2022 with 28.4%, followed by electric power (24.9%), industry (22.9%), agriculture (10%), commercial (7.3%) and residential (6.2%).<ref name=EPAghg_20250319/> The EPA reported 1.8 billion metric tons of [[carbon dioxide]]-equivalent was emitted by the transportation sector in 2022, with carbon dioxide from fossil fuel combustion constituting 97.2% of the emissions.<ref name=EPAghg_20250319/> Of the 1.8 billion metric tons emitted in 2019, 58% was emitted by personal vehicles, 25% was emitted by commercial trucks and busses, 10% was emitted by air travel, 3% is emitted by pipeline, 2% is by rail, and 2% is by water.<ref name=EPA2023>{{Cite web |last=US EPA |first=OAR |date=2023-02-01 |title=Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2021 |url=https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2021 |access-date=2023-04-26 |publisher=Environmental Protection Agency}}</ref>

==See also==
{{Portal|United States|Transport}}
* [[Transportation]]
* [[United States Department of Transportation]]
* [[Transportation in Canada]]
* [[Transportation in Mexico]]
* [[List of U.S. cities with high transit ridership]]
* [[List of countries by vehicles per capita]]
* [[American Public Transportation Association]]
* [[History of rail transport in the United States]]
* [[Plug-in electric vehicles in the United States]]
* [[Road signs in the United States]]
* [[Timeline of United States railway history]]
* [[Transportation safety in the United States]]
* [[Timeline of transportation technology]]

===Location-specific===
{{div col|colwidth=30em}}
*[[Transportation in Atlanta]]
*[[Transportation in Boston]]
*[[Transportation in Buffalo, New York]]
*[[Transportation in Charlotte, North Carolina]]
*[[Transportation in Chicago]]
*[[Transportation in Cincinnati]]
*[[Transportation in Dallas]]
*[[Transportation in Los Angeles]]
*[[Transportation in St. Louis]]
*[[Transportation in Guam]]
*[[Transportation in Hampton Roads]]
*[[Transportation in Houston]]
*[[Transportation in Indianapolis]]
*[[Transportation in the Inland Empire]]
*[[Transportation in Las Vegas]]
*[[Transportation on Long Island]]
*[[Transportation in Louisville, Kentucky]]
*[[Transportation in Memphis, Tennessee]]
*[[Transportation in metropolitan Detroit]]
*[[Transportation in Miami]]
*[[Transportation in New England]]
*[[Transportation in New York City]]
*[[Transportation in Norfolk, Virginia]]
*[[Transportation in Omaha]]
*[[Transportation in Pittsburgh]]
*[[Transportation in Portland, Oregon]]
*[[Transportation in Philadelphia]]
*[[Transportation in Puerto Rico]]
*[[Transportation in Richmond, Virginia]]
*[[Transportation in the Sacramento metropolitan area]]
*[[Transportation in Salt Lake City]]
*[[Transportation in San Diego]]
*[[Transportation in the San Francisco Bay Area]]
*[[Transportation in Seattle]]
*[[Transportation in the United States Virgin Islands]]
*[[Transportation in Washington, D.C.]]
*[[Transportation in Williamsburg, Virginia]]
{{div col end}}

===Funding===

====All modes====

*[[Surface Transportation and Uniform Relocation Assistance Act]]
*[[Intermodal Surface Transportation Efficiency Act]]
*[[Transportation Equity Act for the 21st Century]]
*[[Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users]]
*[[American Recovery and Reinvestment Act of 2009]]

====Mass transportation====
* [[Urban Mass Transportation Act of 1964]]
* [[Urban Mass Transportation Act of 1970]]
* [[National Mass Transportation Assistance Act]]
* [[Project Independence]]

==References==
{{Reflist|refs=
<ref name=rdmbridges>{{Citation |author=Staff |publication-date=May 3, 2012 |year=2012 |title=The challenge of testing and protecting vintage U.S. bridges |periodical=R&D Magazine |publisher=[[Advantage Business Media]] |url=http://www.rdmag.com/News/2012/05/Industries-Transportation-Test-Measurement-The-challenge-of-testing-and-protecting-vintage-US-bridges/ |access-date=May 3, 2012 |archive-date=May 14, 2012 |archive-url=https://web.archive.org/web/20120514145851/http://www.rdmag.com/News/2012/05/Industries-Transportation-Test-Measurement-The-challenge-of-testing-and-protecting-vintage-US-bridges/ |url-status=live }}</ref>
}}

{{CIA World Factbook}}

==Further reading==
* Atack, Jeremy. "Transportation in American Economic History." in Louis P. Cain,  ed., ''The Oxford Handbook of American Economic History'' (2018) 2: 23+ [https://books.google.com/books?id=GclhDwAAQBAJ&dq=Turnpikes&pg=PA23 Excerpt]
* Atack, Jeremy. "Railroads." in ''Handbook of Cliometrics'' ed by Diebolt, Claude, and Michael Haupert, (2018): 1-29.
* Atack, Jeremy, et al. "Did railroads induce or follow economic growth?: Urbanization and population growth in the American Midwest, 1850–1860." ''Social Science History'' 34.2 (2010): 171–197. [https://www.nber.org/papers/w14640.pdf online]
* Bednarek, Janet R. "Open Sky: The Broad Range of Recent Scholarship in Aviation History." ''Mobility in History'' 4.1 (2013): 89–94.
* Belcher, Wyatt Winton. ''The Economic Rivalry Between St. Louis and Chicago: 1850-1880'' (Columbia UP, 1947).
* Cochran, Thomas C. ''Railroad Leaders, 1845-1890'' (Harvard UP, 1953).
* Gordon, Arthur. ''American Heritage History of Flight'' (1962)
* Grant, H. Roger. ''Transportation and the American People'' (Indiana UP,  2019).
* Herrendorf, Berthold, James A. Schmitz, Jr, and Arilton Teixeira. "The role of transportation in US economic development: 1840–1860." ''International Economic Review'' 53.3 (2012): 693–716. [http://www.public.asu.edu/~bherrend/Published%20Papers/IER2012.pdf Online] {{Webarchive|url=https://web.archive.org/web/20210126163956/http://www.public.asu.edu/~bherrend/Published%20Papers/IER2012.pdf |date=January 26, 2021 }}
* {{Hunter-Steamboats-1949}}
* Kirkland, Edward Chase. ''Men, cities and transportation: a study in New England history, 1820-1900'' (2 vol Harvard UP, 1948).
* Lewis, Tom. ''Divided highways: Building the interstate highways, transforming American life'' (Cornell UP, 2013) 
* Pereira, Rui, Alfredo Pereira, and William J. Hausman. "Railroad Infrastructure Investments and Economic Development in the Antebellum United States." ''Journal Of Economic Development'' 42.3 (2017). [http://jed.or.kr/full-text/42-3/1.pdf Online] {{Webarchive|url=https://web.archive.org/web/20191104204512/http://jed.or.kr/full-text/42-3/1.pdf |date=November 4, 2019 }}
* Shaw, Ronald E. ''Canals for a nation: the canal era in the United States, 1790-1860'' (UP of Kentucky, 2014).
* Taylor, George Rogers. ''The Transportation Revolution, 1815-1860''  (1951)
* White, John H. ''Wet Britches and Muddy Boots: A History of Travel in Victorian America'' (Indiana UP, 2013). xxvi + 512 pp. 
* Wolmar, Christian. ''The Great Railway Revolution: The Epic Story of the American Railroad'' (Atlantic Books Ltd, 2012), Popular history.
* Wright, Robert E. "The Pivotal Role of Private Enterprise in America's Transportation Age, 1790-1860." ''Journal of Private Enterprise'' 29.2 (2014): 1+. [http://journal.apee.org/index.php/ajax/GDMgetFile/2014.Spring.JPE_part1.pdf Online]

==External links==
* [https://digitalcollections.nypl.org/collections/the-pageant-of-america-collection#/?tab=navigation&roots=3:fd7c7e50-c611-012f-54b7-58d385a7bc34 594 photographs on American business history, including many on transportation of all types; these are pre-1923 and out of copyright.]
* [https://web.archive.org/web/19970406061206/http://www.dot.gov/ U.S. Department of Transportation] (DOT)
* [http://www.bts.gov/ Bureau of Transportation Statistics] – Part of DOT
* [https://web.archive.org/web/20160604023443/http://www.ntdprogram.gov/ National Transit Database] – Statistics on U.S. public transportation systems from the [https://www.transit.dot.gov/ Federal Transit Administration], part of DOT
* [http://www.apta.com/ American Public Transportation Association]
* [https://usafreightbrokerage.us/ ocean freight services in usa] {{Webarchive|url=https://web.archive.org/web/20191220111343/https://usafreightbrokerage.us/ |date=December 20, 2019 }}

{{U.S. political divisions transportation}}
{{Social issues in the United States}}
{{Economy of the United States}}
{{Americas topic|Transportation in}}
{{World topic|Transportation in|noredlinks=yes}}

{{DEFAULTSORT:Transportation In The United States}}
[[Category:Transportation in the United States| ]]