View source for Interstate 99

{{Short description|Interstate Highway in Pennsylvania and New York}}
{{Use mdy dates|date=July 2014}}
{{Use American English|date=January 2023}}
{{Infobox road
| country = USA
| type = I
| route = 99
| map = {{maplink-road|frame-height=290|from=Interstate 99.map|from2=Future Interstate 99.map}}
| map_custom = yes
| map_notes = I-99 highlighted in red and Future I-99 in blue
| established = {{start date|1998}}<ref name="aashto" />
| section1 = Southern segment
| length_mi1 = 85.78
| length_ref1 = <ref name="fhwa">{{cite web |last=Starks |first=Edward |date=January 27, 2022 |title=Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways |url=https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table01.cfm |access-date=January 21, 2023 |work=FHWA Route Log and Finder List |publisher=[[Federal Highway Administration]]}}</ref>
| direction_a1 = South
| terminus_a1 = {{Jct|state=PA|US|220|US-Bus|220|dab2=Bedford}} near [[Bedford, Pennsylvania|Bedford, PA]]
| junction1 = <!-- Major junctions only; Only 5-8 most major intersections and cities belong here; please read [[WP:USRD/STDS]] for more info -->
*{{Jct|state=PA|PA|56}} near [[Cessna, Pennsylvania|Cessna, PA]]
*{{Jct|state=PA|US|22}} near [[Altoona, Pennsylvania|Altoona, PA]]
*{{Jct|state=PA|PA|453}} in [[Tyrone, Pennsylvania|Tyrone, PA]]
*{{Jct|state=PA|US|322}} near [[State College, Pennsylvania|State College, PA]]
*{{Jct|state=PA|PA|150}} near [[Bellefonte, Pennsylvania|Bellefonte, PA]]
*{{Jct|state=PA|PA|26}} near [[Pleasant Gap, Pennsylvania|Pleasant Gap, PA]]
| direction_b1 = North
| terminus_b1 = {{Jct|state=PA|US|220|PA|26}} near Bellefonte, PA
| section2 = Northern segment
| length_mi2 = 75.90
| length_ref2 = <ref name="fhwa" />
| direction_a2 = South
| terminus_a2 = {{jct|state=PA|I|180|US|15|US|220}} in [[Williamsport, Pennsylvania|Williamsport, PA]]
| junction2 = <!-- Major junctions only; Only 5-8 most major intersections and cities belong here; please read [[WP:USRD/STDS]] for more info -->
*{{Jct|state=PA|US|6}} in [[Mansfield, Pennsylvania|Mansfield, PA]]
*{{Jct|state=NY|NY|417}} near [[Addison, New York|Addison, NY]]
| direction_b2 = North
| terminus_b2 = {{jct|state=NY|I|86|US|15|NY|17|NY|352}} near [[Painted Post, New York|Painted Post, NY]]
| states = [[Pennsylvania]], [[New York (state)|New York]]
| counties = '''PA:''' [[Bedford County, Pennsylvania|Bedford]], [[Blair County, Pennsylvania|Blair]], [[Centre County, Pennsylvania|Centre]]<br>'''NY:''' [[Steuben County, New York|Steuben]]
| browse = {{pa browse|previous_type=PA|previous_route=98|route=[[Pennsylvania State Route System|PA]]|next_type=PA|next_route=99}}
{{ny browse|previous_type=NY|previous_route=98|route=[[List of numbered highways in New York|NY]]|next_type=NY|next_route=99}}
}}
'''Interstate&nbsp;99''' ('''I-99''') is an [[Interstate Highway|interstate highway]] in the United States with two segments: one located in central [[Pennsylvania]] and the other in northern Pennsylvania into southern [[New York (state)|New York]] along US 15.<ref name=I99NY>{{cite news |author= [Staff writer] |title= Corning Area Now Has 2&nbsp;Interstates: US&nbsp;15 Designated I-99 to Pa. Border |url= http://www.stargazette.com/article/20140627/NEWS01/306270011/Corning-area-now-has-2-interstates-U-S-15-designated-I-99-to-Pa-border |access-date= June 28, 2014 |work= Star-Gazette |date= June 28, 2014 |url-status= dead |archive-url= https://web.archive.org/web/20140715105338/http://www.stargazette.com/article/20140627/NEWS01/306270011/Corning-area-now-has-2-interstates-U-S-15-designated-I-99-to-Pa-border?nclick_check=1 |archive-date= July 15, 2014 |df= mdy-all }}</ref> The southern terminus of the route is near exit&nbsp;146 of the [[Pennsylvania Turnpike]] ([[Interstate 70 in Pennsylvania|I-70]]/[[Interstate 76 in Pennsylvania|I-76]]) north of [[Bedford, Pennsylvania|Bedford]], where the road continues south as [[U.S. Route 220 in Pennsylvania|U.S. Route&nbsp;220]] (US&nbsp;220). The northern terminus of the Pennsylvania segment is at an at-grade intersection with Musser Lane near [[Interstate 80 in Pennsylvania|I-80]] near [[Bellefonte, Pennsylvania|Bellefonte]]. The northern segment is entirely [[concurrency (road)|concurrent]] with [[U.S. Route 15|US&nbsp;15]], beginning at [[Interstate 180 (Pennsylvania)|I-180]] in Williamsport northward into New York to an interchange with [[Interstate 86 in New York|I-86]] in [[Corning (city), New York|Corning]]. Within Pennsylvania, I-99 passes through [[Altoona, Pennsylvania|Altoona]] and [[State College, Pennsylvania|State College]]—the latter home to the [[Pennsylvania State University]]—and is entirely concurrent with US&nbsp;220. 

In November 2024, the northern segment was extended down US 15 to I-180 in Williamsport, entirely concurrent with US 15.<ref>{{AASHTO minutes|year=2024A|access-date = November 12, 2024}}</ref> Long-term plans call for the two segments of I-99 to be connected using portions of I-80 and US&nbsp;220 through Pennsylvania. The only current progress on the connection is the direct access interchange at I-80.

Unlike most interstate highway numbers, which were assigned by the [[American Association of State Highway and Transportation Officials]] (AASHTO) to fit into a grid, I-99's number was written into Section&nbsp;332 of the [[National Highway System Designation Act of 1995]] by [[Bud Shuster]], then-chair of the [[US House Committee on Transportation and Infrastructure]], the bill's sponsor, and the representative of the district through which the highway runs. I-99 breaks the AASHTO numbering pattern associated with interstate highways, as it would be expected to lie east of [[Interstate 97|I-97]] but instead lies east of [[Interstate 79|I-79]] and west of [[Interstate 81|I-81]].

==Route description==
{{lengths table|length_ref=<ref name="fhwa" />}}
|-
|{{abbr|PA|Pennsylvania}}
|{{convert|149.00|mi|km|disp=table}}
|-
|{{abbr|NY|New York}}
|{{convert|12.68|mi|km|disp=table}}
|-
|Total
|{{convert|161.68|mi|km|disp=table}}
|}
===Southern segment===
{{see also|U.S. Route 220 in Pennsylvania}}
I-99 begins at an indirect interchange with US&nbsp;220 and the [[Pennsylvania Turnpike]] ([[Interstate 70 in Pennsylvania|I-70]]/[[Interstate 76 in Pennsylvania|I-76]]) north of [[Bedford, Pennsylvania|Bedford]]. It begins [[Concurrency (road)|concurrent]] with [[U.S. Route 220 in Pennsylvania|US&nbsp;220]], which continues south from the interchange toward the [[Maryland]] state line as a two-lane highway known as the Appalachian Thruway. To access the turnpike, drivers are required to use a short segment of [[U.S. Route 220 Business (Bedford, Pennsylvania)|US&nbsp;220 Business]] (US&nbsp;220 Bus.). North of the turnpike junction, the [[controlled-access highway|freeway]] becomes the Bud Shuster Highway as it heads through a rural portion of [[Bedford County, Pennsylvania|Bedford County]]. It connects to [[Pennsylvania Route&nbsp;56]] (PA&nbsp;56) just west of [[Bedford County Airport]] at exit&nbsp;3 and [[Pennsylvania Route 869|PA&nbsp;869]] at exit&nbsp;7 before crossing into [[Blair County, Pennsylvania|Blair County]]. Here, it meets [[Pennsylvania Route 164|PA&nbsp;164]] north of [[East Freedom, Pennsylvania|East Freedom]] at exit&nbsp;23 prior to entering the [[Altoona, Pennsylvania|Altoona]] area.<ref name="google">{{google maps |url=https://maps.google.com/maps?f=d&source=s_d&saddr=40.057583,-78.517853&daddr=I-99+N%2FPA-26+N&geocode=%3BFSy6cAIdQABe-w&hl=en&mra=mi&mrsp=0&sz=16&sll=40.057069,-78.513815&sspn=0.012055,0.027831&ie=UTF8&z=16 |title= Overview Map of I-99 |access-date=July 18, 2010}}</ref>

In [[Hollidaysburg, Pennsylvania|Hollidaysburg]], a borough south of the city, I-99 and US&nbsp;220 connect to [[U.S. Route 22 in Pennsylvania|US&nbsp;22]] at exit&nbsp;28, a large modified [[trumpet interchange]]. This junction allows travelers to head west toward [[Ebensburg, Pennsylvania|Ebensburg]], [[Johnstown, Pennsylvania|Johnstown]], and [[Pittsburgh]]. The freeway continues to Altoona itself, where it indirectly connects to [[Pennsylvania Route 36|PA&nbsp;36]] via exit&nbsp;32. Unlike the original routing of US&nbsp;220 which goes through the city center, I-99 and US&nbsp;220 mostly bypass it to the east, connecting to the city via streets leading eastward from the downtown district. At the northern edge of Altoona, [[Pennsylvania Route 764|PA&nbsp;764]] joins the old alignment of US&nbsp;220 and parallels I-99 north for {{convert|3|mi|km|spell=in}} toward [[Bellwood, Pennsylvania|Bellwood]]. PA&nbsp;764 leaves old US&nbsp;220 about {{convert|2|mi|km|spell=in}} south of Bellwood, however, and terminates at I-99 exit&nbsp;39. Bellwood itself is served by exit&nbsp;41, which leads to [[Pennsylvania Route 865|PA&nbsp;865]].<ref name="google" />

[[File:I-99 N foliage.jpg|thumb|left|I-99 north near Bald Eagle, Pennsylvania in October 2011]]
The highway veers northeastward from Bellwood to serve the borough of [[Tyrone, Pennsylvania|Tyrone]], located at the junction of old US&nbsp;220 and [[Pennsylvania Route 453|PA&nbsp;453]]. Access to the borough is made by way of exit&nbsp;48, which serves PA&nbsp;453. Past Tyrone, I-99 and US&nbsp;220 head through sparsely populated areas of Blair and [[Centre County, Pennsylvania|Centre]] counties. For this reason, only three exits exist between Tyrone and [[State College, Pennsylvania|State College]]: exit&nbsp;52, serving [[Pennsylvania Route 350|PA&nbsp;350]] and the small community of [[Bald Eagle, Pennsylvania|Bald Eagle]], and exits&nbsp;61 and 62, which connect to [[U.S. Route 322 in Pennsylvania|US&nbsp;322]] and the borough of [[Port Matilda, Pennsylvania|Port Matilda]]. Here, US&nbsp;322 joins I-99 and US&nbsp;220 and follows them eastward to the State College area.<ref name="google" />

[[File:2015-12-14 12 41 37 View north along Interstate 99 and U.S. Route 220 at Exit 73 (East U.S. Route 322, Penn State University, State College) in College Township, Pennsylvania.jpg|right|thumb|I-99/US&nbsp;220 northbound at split with US&nbsp;322 eastbound in [[College Township, Pennsylvania|College Township]], near State College]]
At exit&nbsp;68 ([[U.S. Route 322 Business (State College, Pennsylvania)|US&nbsp;322 Bus.]]), I-99 merges into the [[Mount Nittany Expressway]], an older, northerly bypass of State College. I-99, US&nbsp;220, and US&nbsp;322 follow the expressway to the Mount Nittany Interchange, a [[directional T interchange]] located on the northern fringe of the [[Pennsylvania State University]] campus. [[Beaver Stadium]], the home of the [[Penn State Nittany Lions football]] team, is visible from I-99 at this point. US&nbsp;322 continues east through the interchange to follow the Mount Nittany Expressway while I-99 and US&nbsp;220 split from US&nbsp;322 and head northeastward toward [[Pleasant Gap, Pennsylvania|Pleasant Gap]], which I-99 connects to via exit&nbsp;81 and [[Pennsylvania Route 26|PA&nbsp;26]]. At this point, PA&nbsp;26 joins the freeway and follows it to [[Bellefonte, Pennsylvania|Bellefonte]], served by exit&nbsp;83 and [[Pennsylvania Route 550|PA&nbsp;550]]. The southern segment of I-99 ends about {{convert|1.75|mi|km}} later at an intersection with Musser Lane though the divided highway continues {{convert|0.33|mi|km}} northeast to an interchange with [[Interstate 80 in Pennsylvania|I-80]], where PA&nbsp;26 continues north and US&nbsp;220 joins I-80 east.<ref name="google" />

===Northern segment===
{{main|U.S. Route 15 in New York}}
[[File:US 15 south at Presho NY exit.jpg|thumb|right|Looking southward along US&nbsp;15 (now I-99) from the Smith Road overpass in Presho prior to the road's completion. The highway previously narrowed from four to two lanes in the background]]
The northern segment of I-99 is entirely concurrent with [[U.S. Route 15 in New York|US&nbsp;15]] and starts at the junction of US 220, US 15, and [[Interstate_180_(Pennsylvania)|I-180]]. I-99 crosses through mountainous terrain in [[Lycoming County, Pennsylvania|Lycoming]] and [[Tioga County, Pennsylvania|Tioga]] counties, bypassing [[Mansfield, Pennsylvania|Mansfield]]. The route crosses the Pennsylvania–[[New York (state)|New York]] border north of [[Lawrenceville, Pennsylvania]]. A four-lane freeway through the [[Steuben County, New York|Steuben County]] town of [[Lindley, New York|Lindley]], I-99 crosses through a rock cut, making a large bend to the north and bypassing the hamlet of [[Presho, New York|Presho]]. The freeway enters a [[partial cloverleaf interchange]] with [[County Route 5 (Steuben County, New York)|County Route&nbsp;5]] (CR&nbsp;5; Smith Road). After CR&nbsp;5, I-99 turns northeast through the town of [[Erwin, New York|Erwin]], running to the west of the Indian Hills Golf Club. Making a gradual bend further to the northeast, the freeway crosses the [[Canisteo River]] and enters the hamlet of Erwins, where it enters a [[diamond interchange]] with [[New York State Route 417]] (NY&nbsp;417; Addison Road). After NY&nbsp;417, it then turns alongside [[Norfolk Southern Railway]]'s [[Southern Tier Line]] (former [[Erie Railroad]] main line). Now paralleling the tracks and NY&nbsp;417, I-99/US&nbsp;15 crosses through Erwin, entering exit&nbsp;11, which connects to NY&nbsp;417 once again, next to Gang Mills Yard,<ref name="bing">{{bing maps|url=http://binged.it/Qzs6yW|title=overview map of Interstate 99 in New York|access-date=July 24, 2012}}</ref> the site of former [[Painted Post station]].<ref name="yanosey">{{cite book|last=Yanosey|first=Robert J.|others= Lawton, Devon (photographer)|title=New York|publisher=Morning Sun Books|location=Scotch Plains, New Jersey|date=2006|series=Erie Railroad Facilities in Color|volume=2: NY|page=71|isbn=1-58248-196-2}}</ref>

[[File:Interstate 99 entering New York.jpg|thumb|left|I-99/US&nbsp;15 entering New York]]
After Gang Mills Yard, I-99 crosses through the [[Gang Mills, New York|Gang Mills]] section of Erwin, entering a large interchange at the northern end of the neighborhood. Signed exit&nbsp;12, this interchange serves [[County Route 107 (Steuben County, New York)|CR&nbsp;107]] (Robert Dann Drive) via NY&nbsp;417. After CR&nbsp;107, I-99 enters a large interchange that utilizes several flyover ramps between I-99, US&nbsp;15, [[Interstate 86 in New York|I-86]], and [[New York State Route 17|NY&nbsp;17]] ([[Southern Tier Expressway]]). Ramps are also present, connecting to [[New York State Route 352|NY&nbsp;352]]. This interchange serves as the northern terminus of both I-99 and US&nbsp;15.<ref name="bing" />

==History==
===Origins===
[[File:I99SkyTop.jpg|thumb|upright|2002 photo of the I-99 excavation, looking south from [[Julian, Pennsylvania|Julian]] at the area where acidic rock was exposed on [[Bald Eagle Mountain]]]]
Corridor O of the [[Appalachian Development Highway System]] was assigned in 1965,{{Citation needed|date=May 2011}} running from [[Cumberland, Maryland]] ([[Corridor E (ADHS)|Corridor E]], now [[Interstate 68|I-68]]) to Bellefonte ([[Interstate 80 in Pennsylvania|I-80]]) along [[U.S. Route 220|US&nbsp;220]].<ref>{{cite web |url=http://www.arc.gov/images/programs/transp/adhs_status_report_2009/ADHS2009StatusReportGeneralReport.pdf |title=Status of the Appalachian Development Highway System as of September 30, 2009 |date=December 2009 |publisher=[[Appalachian Regional Commission]] |access-date=July 18, 2010 |archive-date=October 5, 2010 |archive-url=https://web.archive.org/web/20101005175607/http://www.arc.gov/images/programs/transp/adhs_status_report_2009/ADHS2009StatusReportGeneralReport.pdf |url-status=dead }}</ref> The portion in [[Pennsylvania]], from [[Bedford, Pennsylvania|Bedford]] north to [[Bald Eagle, Pennsylvania|Bald Eagle]], was upgraded to a [[controlled-access highway|freeway]] in stages from the 1960s to the 1990s. The first section, from [[U.S. Route 30 in Pennsylvania|US&nbsp;30]] in Bedford to [[Pennsylvania Route 56|PA&nbsp;56]] near [[Cessna, Pennsylvania|Cessna]], opened in the latter half of the 1960s.<ref>{{cite map |title=Pennsylvania |publisher=[[Sun Oil Company]] |year=1964 |edition=1964–65 |cartography=[[H. M. Gousha Company]]}}</ref><ref name="1970map">{{Cite FTP |url=ftp://ftp.dot.state.pa.us/public/pdf/BPR_pdf_files/Maps/Statewide/Historic_OTMs/1970fr.pdf |title=Official Map of Pennsylvania |format=PDF |year=1970 |server=[[Pennsylvania Department of Highways]] |url-status=dead |access-date=July 18, 2010 }}</ref> Two more sections—from PA&nbsp;56 north to modern exit&nbsp;15 in [[Blair County, Pennsylvania|Blair County]] and from [[Charlottsville, Pennsylvania|Charlottsville]] (exit&nbsp;45) to Bald Eagle—were completed in the 1970s.<ref name="1970map" /><ref name="1980map">{{Cite FTP |url=ftp://ftp.dot.state.pa.us/public/pdf/BPR_pdf_files/Maps/Statewide/Historic_OTMs/1980fr.pdf |title=Commonwealth of Pennsylvania Official Transportation Map |format=PDF |year=1980 |server=[[Pennsylvania Department of Transportation]] |url-status=dead |access-date=July 18, 2010 }}</ref> The portion between exit&nbsp;15 and [[Altoona, Pennsylvania|Altoona]] (exit&nbsp;33) was finished in the 1980s<ref name="1980map" /><ref>{{Cite FTP |url=ftp://ftp.dot.state.pa.us/public/pdf/BPR_pdf_files/Maps/Statewide/Historic_OTMs/1989fr.pdf |title=Pennsylvania Official Transportation Map |format=PDF |year=1989 |server=[[Pennsylvania Department of Transportation]] |url-status=dead |access-date=July 18, 2010 }}</ref> while the segment between modern exits&nbsp;33 and 45 was opened by 1997.<ref>{{cite map |publisher=[[Rand McNally and Company]] |title=Easy-to-Read Travel Atlas: United States–Canada–Mexico |year=1997 |page=44 |isbn=0-528-81575-X}}</ref>

[[File:2021-10-27 13 22 04 View north along Interstate 99 and U.S. Route 220 just north of Exit 41 in Antis Township, Blair County, Pennsylvania.jpg|thumb|left|I-99 and US&nbsp;220 northbound past PA&nbsp;865 near Bellwood]]
In 1991, the [[Intermodal Surface Transportation Efficiency Act]] (ISTEA) was signed into law.<ref name="istea-a">{{Cite web |title=Bill Summary & Status H.R.2950 |url=http://thomas.loc.gov/cgi-bin/bdquery/z?d102:HR02950: |access-date=June 23, 2014 |archive-date=December 15, 2012 |archive-url=https://web.archive.org/web/20121215195446/http://thomas.loc.gov/cgi-bin/bdquery/z?d102:HR02950: |url-status=dead }}</ref> It included a number of High Priority Corridors, one of which—Corridor&nbsp;9—ran along US&nbsp;220 from Bedford to [[Williamsport, Pennsylvania|Williamsport]], and then north on [[U.S. Route 15|US&nbsp;15]] to [[Corning (city), New York|Corning, New York]].<ref name="istea-text">{{Cite web |title=Bill Text H.R.2950 |url=http://thomas.loc.gov/cgi-bin/query/F?c102:7:./temp/~c102L9Hp2g:e206581: |access-date=June 23, 2014 }}{{Dead link|date=August 2021 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The [[National Highway System Designation Act of 1995]] amended ISTEA; among these amendments were that "the portion of the route referred to in subsection (c)(9) [Corridor 9] is designated as Interstate Route I-99."<ref name="nhsda-text">{{Cite web |title=National Highway System Designation Act of 1995 |url=http://www.gpo.gov/fdsys/pkg/PLAW-104publ59/html/PLAW-104publ59.htm |access-date=June 23, 2014 }}</ref> This was the first interstate highway number to be written into law rather than to be assigned by [[American Association of State Highway and Transportation Officials|AASHTO]]. The number was specified by Representative [[Bud Shuster]], who said that the standard spur numbering was not "catchy"; instead, I-99 was named after a street car, No. 99, that took people from Shuster's hometown of [[Glassport, Pennsylvania|Glassport]] to [[McKeesport, Pennsylvania|McKeesport]]. I-99 breaks the AASHTO numbering pattern associated with interstate highways, since it lies east of [[Interstate 79|I-79]] but west of [[Interstate 81|I-81]] (the number suggests it would be located very close to the [[Atlantic Ocean]], east of [[Interstate 95|I-95]]).<ref name="debate">{{cite news |title=Road Stirs Up Debate, Even on Its Name |newspaper=[[The New York Times]] |date=December 27, 2008 |url=https://www.nytimes.com/2008/12/28/us/28highway.html |first=Sean D. |last=Hamill}}</ref>

===Designation and Bald Eagle Mountain===
On November 6, 1998, AASHTO formally approved the I-99 designation, which initially extended {{convert|51.2|mi|km}} from the [[Pennsylvania Turnpike]] in Bedford to [[Pennsylvania Route 350|PA&nbsp;350]] in Bald Eagle.<ref name="aashto">{{cite web |url=http://cms.transportation.org/sites/route/docs/1998-USRN_Cmte.pdf |publisher=[[American Association of State Highway and Transportation Officials]] |title=Report of the Special Committee on U.S. Route Numbering to the Standing Committee on Highways |date=November 7, 1998 |access-date=July 18, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20061012224238/http://cms.transportation.org/sites/route/docs/1998-USRN_Cmte.pdf |archive-date=October 12, 2006 |df=mdy-all }}</ref> In 2002, plans were set in motion to extend I-99 northeast from Bald Eagle to [[State College, Pennsylvania|State College]] via [[Port Matilda, Pennsylvania|Port Matilda]].<ref name="long road">{{cite news |url=http://www.altoonamirror.com/page/content.detail/id/513588.html |title=Long road for I-99 comes to end |last=Bock |first=Greg |date=November 25, 2008 |newspaper=[[Altoona Mirror]] |access-date=July 18, 2010}}</ref> The extension was fraught with issues, however. The proposed alignment for the highway north to Port Matilda proved to be controversial: while environmentalists called for I-99 to be constructed in the valley below [[Bald Eagle Mountain]], the [[Pennsylvania Department of Transportation]] (PennDOT) and valley residents favored a routing that took the freeway above the valley and along the side of the ridge.<ref>{{cite news |url=http://www.post-gazette.com/healthscience/20021207highway2.asp |title=I-99 segment gets environmental OK |last=Gibb |first=Tom |date=December 7, 2002 |newspaper=[[Pittsburgh Post-Gazette]] |access-date=July 19, 2010}}</ref> Farther north, the widening of [[Skytop, Centre County, Pennsylvania|Skytop]], the mountain cut that [[U.S. Route 322 in Pennsylvania|US&nbsp;322]] uses to traverse Bald Eagle Mountain, resulted in the exposure of acidic [[pyrite]] rock in 2003.<ref name="long road" />

[[File:Route 322 WB 2.jpg|thumb|left|2006 photo of the westbound approach to the Mount Nittany Interchange on westbound US 322. The blank spots on the overhead signs were reserved for I-99 shields, which have since been put up.]]
Work on the segment ceased one year later<ref name="long road" /> as PennDOT attempted to stop the flow of acidic runoff from the site. The state remedied the situation by removing {{convert|1000000|yd3|m3}} of pyrite and replacing it with a mix of [[limestone]] and fill, a process that took two years and cost $83&nbsp;million (equivalent to ${{Inflation|US|83|2005|r=0}}&nbsp;million in {{Inflation/year|US}}).<ref name="debate" /> With the environmental issues settled, construction resumed on the portion of the freeway south of Skytop Mountain. The section from Bald Eagle to Port Matilda was opened to traffic on December 17, 2007,<ref>{{cite news |url=http://www.altoonamirror.com/page/content.detail/id/502818.html |title=Long-awaited I-99 stretch opens |last=Bock |first=Greg |date=December 18, 2007 |newspaper=Altoona Mirror |access-date=July 19, 2010}}</ref> while the remaining section between Port Matilda and the west end of the [[Mount Nittany Expressway]] near State College was completely opened on November 17, 2008.<ref name="long road" /> In all, the 18-mile Bald Eagle–State College section of I-99 cost $631&nbsp;million (equivalent to ${{Inflation|US|631|2008|r=0}}&nbsp;million in {{Inflation/year|US}}) to construct.<ref name="debate" />

I-99 was extended northeastward to meet [[Interstate 80 in Pennsylvania|I-80]] northeast of [[Bellefonte, Pennsylvania|Bellefonte]] following the completion of the Bald Eagle–State College segment. The connection was made by way of the preexisting Mount Nittany Expressway and another, unnamed limited-access highway connecting the State College bypass to the Bellefonte area.<ref name="debate" /> The portion of the latter highway north of the [[Pennsylvania Route 26|PA&nbsp;26]] interchange was originally built in the 1970s as a [[two-lane expressway|two-lane freeway]] connecting [[Pleasant Gap, Pennsylvania|Pleasant Gap]] to I-80. At the time, it was designated solely as PA&nbsp;26.<ref name="1970map" /><ref name="1980map" /> It was widened to four lanes in 1997.{{Citation needed|date=July 2010}} The piece connecting the PA&nbsp;26 freeway to the Mount Nittany Expressway was completed in 2002.{{Citation needed|date=July 2010}} [[U.S. Route 220 in Pennsylvania|US&nbsp;220]] was rerouted via US&nbsp;322 and the new road, and the old alignment of US&nbsp;220 north of US&nbsp;322 was designated [[U.S. Route 220 Alternate (State College, Pennsylvania)|US&nbsp;220 Alternate]] (US&nbsp;220 Alt.) on May 30, 2003.<ref>{{cite web |url=http://cms.transportation.org/sites/route/docs/2003-USRN_Cmte.pdf |publisher=American Association of State Highway and Transportation Officials |title=Report of the Special Committee on U.S. Route Numbering to the Standing Committee on Highways |date=May 31, 2003 |access-date=July 18, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20070204073739/http://cms.transportation.org/sites/route/docs/2003-USRN_Cmte.pdf |archive-date=February 4, 2007 |df=mdy-all }}</ref> This extension, however, did not include an interchange with I-80, resulting in I-99 terminating at an at-grade intersection with Musser Lane just before reaching I-80.

Further north, one short segment of two-lane highway remained between Lawrenceville, Pennsylvania, and Presho, New York, almost entirely within New York. In the early 2010s, {{Convert|5|mi|km|spell=in}} of new freeway was constructed to connect the existing freeway segments. This provided through traffic with a continuous freeway from Williamsport, Pennsylvania, to Corning, New York, and removed traffic from the overburdened two-lane section of US&nbsp;15, which was retired to county route status as [[County Route 115 (Steuben County, New York)|CR&nbsp;115]]. On June 27, 2014, New York Governor [[Andrew Cuomo]] announced that the interstate-grade US 15 freeway from the Pennsylvania border to I-86 in Corning was officially signed as I-99.<ref name=I99NY/>

==Future==
[[File:Future I-99 Corridor.jpg|thumb|right|"Future I-99 Corridor" sign on US&nbsp;15 southbound north of [[Williamsport, Pennsylvania|Williamsport]]]]
Though there is no specific date for completion, long-term plans call for the two segments of I-99 to be connected via [[U.S. Route 220 in Pennsylvania|US 220]] from [[Bellefonte, Pennsylvania|Bellefonte]] to [[Williamsport, Pennsylvania|Williamsport]], running concurrent with [[Interstate 80 in Pennsylvania|I-80]] as US 220 currently does, and continue northward along [[U.S. Route 15 in Pennsylvania|US 15]] from Williamsport to the New York border. The entire portion of US 15 involved has been upgraded to [[Interstate Highway standards|interstate highway standards]] in anticipation of the I-99 designation, but some sections of US 220 still require upgrades, primarily in the vicinity of both interchanges with I-80 and between [[Jersey Shore, Pennsylvania|Jersey Shore]] and [[Linden, Pennsylvania|Linden]]. Signs have been erected along the present US 220 and US 15 between Bellefonte and Corning marking the route as the "Future I-99 Corridor".<ref>{{Cite web|url=http://www.m-plex.com/roads/pamplex/mp_i99_us15.html|title=US 15/Future I-99 Multiplex - Central PA/MD Roads|website=www.m-plex.com|access-date=2019-01-13}}</ref> Some of this section of road has also received exit number designations.

PennDOT is currently in the process of buliding a high-speed interchange connecting I-99 to I-80 near [[Bellefonte, Pennsylvania|Bellefonte]]. The new interchange will eliminate local access between [[Pennsylvania Route 26|PA&nbsp;26]] (Jacksonville Road) and I-80, which is provided by a new exit {{Convert|2|mi|km|spell=in}} to the east. The first phase of the project built the local access interchange between PA&nbsp;26 and I-80. Construction on the local access interchange began on July 27, 2020. The local access interchange was opened to traffic on November 10, 2022, with a ribbon-cutting ceremony held.<ref name="Phases">{{cite news |last1=Sinderson |first1=Gary |title=First phase of Interstate 99/I-80 interchange project complete |url=https://wjactv.com/news/local/first-phase-of-interstate-99i-80-interchange-project-complete |access-date=5 May 2023 |work=WJAC |date=10 November 2022 |language=en}}</ref><ref>{{cite news|last=Kines|first=Halie|title=After a 'long road,' the first phase of the Jacksonville Road project is open in Centre County|work=Centre Daily Times|date=November 11, 2022|url=https://www.centredaily.com/news/local/community/bellefonte/article268392837.html|access-date=November 15, 2022}}</ref> The local access interchange between PA&nbsp;26 and I-80 was funded in part by a $35-million federal grant, with a total estimated cost of $52&nbsp;million. The second phase of the project will make improvements to Jacksonville Road between the new interchange and the junction between I-80, and the third phase will build the high-speed interchange between I-80 and I-99. Bidding on the second and third phases was planned to begin in March 2022, with the improvements to Jacksonville Road to be finished by December 2023 and the high-speed interchange to be completed by December 2025.<ref name=gazette2019>{{cite news|title=PennDOT Details New Local Access Tied to I-80/I-99 Interchange Project|work=Centre County Gazette|date=March 1, 2019|url=http://www.statecollege.com/news/local-news/penndot-details-new-local-access-tied-to-i80i99-interchange-project,1479437/|access-date=March 2, 2019|archive-date=March 1, 2019|archive-url=https://web.archive.org/web/20190301190947/http://www.statecollege.com/news/local-news/penndot-details-new-local-access-tied-to-i80i99-interchange-project,1479437/|url-status=dead}}</ref> However, the bids for the other phases had not been released as of May 2023.<ref name="Phases" /> {{As of|June 2024}}, bidding began on the final phases. The second phase, the Jacksonville Road (PA 26) project is expected to take two years, cost $6.9 million and completion is now scheduled for the middle of 2026. Completion of the third and final phase, the $246 million high-speed interchange, is now expected in 2030.<ref name=statecollege2024>{{cite news|title=Next Phases of I-80/I-99 High Speed Interchange Project to Begin This Year|work=StateCollege.com|date=April 18, 2024|url=https://www.statecollege.com/articles/local-news/next-phases-of-i-80-i-99-high-speed-interchange-project-to-begin-this-year/|access-date=June 5, 2024}}</ref>

During a 2002 taskforce meeting for I-99, it was suggested that [[Interstate 390|I-390]], which extends north from I-86 {{convert|24|mi|km}} west of the I-86/I-99 junction near Corning and which crosses I-90 and terminates in the greater [[Rochester metropolitan area, New York|Rochester metropolitan area]], be redesignated as I-99 once the I-80 to I-86 portion of that route is completed. The idea posits that I-390 is a logical extension of the I-99 corridor because I-99's predecessor, US&nbsp;15, originally extended to Rochester. No official moves to accomplish this have been taken.{{Cn|date=June 2023}}

==Exit list==
{{jcttop|exit|length_ref=<ref>{{Cite FTP |author=Bureau of Maintenance and Operations |url=ftp://ftp.dot.state.pa.us/public/Bureaus/BOMO/RM/RITS/Annual%20Electronic%20SLDs%20by%20County/ |title=Roadway Management System Straight Line Diagrams |date=January 2015 |edition=2015 |server=Pennsylvania Department of Transportation |url-status=dead |access-date=June 30, 2015 }}
*[ftp://ftp.dot.state.pa.us/public/Bureaus/BOMO/RM/RITS/Annual%20Electronic%20SLDs%20by%20County/District%209/Bedford%20Co.%20No%20Pipes.pdf Bedford County]{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}} (PDF)
*[ftp://ftp.dot.state.pa.us/public/Bureaus/BOMO/RM/RITS/Annual%20Electronic%20SLDs%20by%20County/District%209/Blair%20Co.%20No%20Pipes.pdf Blair County]{{Dead link|date=November 2025 |bot=InternetArchiveBot }} (PDF)
*[ftp://ftp.dot.state.pa.us/public/Bureaus/BOMO/RM/RITS/Annual%20Electronic%20SLDs%20by%20County/District%202/Centre%20Co.%20No%20Pipes.pdf Centre County]{{Dead link|date=November 2025 |bot=InternetArchiveBot }} (PDF)</ref><ref name="inventory">{{cite web |url=https://www.dot.ny.gov/divisions/engineering/technical-services/hds-repository2/INV_2009-10-01_Steuben.csv |title=Steuben County Inventory Listing |date=October 1, 2009 |publisher=[[New York State Department of Transportation]] |format=CSV |access-date=January 17, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20130408115028/https://www.dot.ny.gov/divisions/engineering/technical-services/hds-repository2/INV_2009-10-01_Steuben.csv |archive-date=April 8, 2013 }}</ref>|state_col=State}}
{{PAint|exit
|sspan=49
|county=Bedford
|cspan=5
|location=Bedford Township
|ctdab=Bedford
|lspan=3
|mile=0.000
|mspan=2
|type=concur
|exit=
|road={{jct|state=PA|US|220|dir1=south|to2=to|US|30|location1=[[Cumberland, Maryland|Cumberland]]}}
|notes=Southern end of US 220 concurrency; continuation south
}}
{{PAint|exit
|mile=none
|exit=1
|road={{jct|state=PA|to1=yes|I-Toll|70|I-Toll|76|PATP||city1=Pittsburgh|city2=Harrisburg}}
|notes=Access via [[U.S. Route 220 Business (Bedford, Pennsylvania)|US&nbsp;220 Bus.]]}}
{{PAint|exit
|mile=2.892
|exit=3
|road={{jct|state=PA|PA|56|name1=[[U.S. Route 220 Business (Bedford, Pennsylvania)|US&nbsp;220 Bus.]] south|city1=Johnstown|city2=Cessna}}
|notes=}}
{{PAint|exit
|location=East St. Clair Township
|ctdab=Bedford
|mile=6.597
|exit=7
|road={{jct|state=PA|PA|869|city1=St. Clairsville|city2=Osterburg}}
|notes=}}
{{PAint|exit
|location=King Township
|ctdab=Bedford
|mile=10.112
|exit=10
|road=[[Blue Knob State Park]]
|notes=Access via Sarah Furnace Road}}
{{PAint|exit
|county=Blair
|cspan=11
|location=Greenfield Township
|ctdab=Blair
|mile=14.900
|exit=15
|road=[[Claysburg, Pennsylvania|Claysburg]], King
|notes=Access via [[U.S. Route 220 Business (Altoona, Pennsylvania)|US&nbsp;220 Bus.]]}}
{{PAint|exit
|location=Freedom Township
|ctdab=Blair
|mile=22.798
|exit=23
|road={{jct|state=PA|PA|36|PA|164|to3=to|US|22|dir3=east|city1=Roaring Spring|city2=Portage|city3=Hollidaysburg}}
|notes=}}
{{PAint|exit
|location=Allegheny Township
|ctdab=Blair
|mile=28.045
|exit=28
|road={{jct|state=PA|US|22|city1=Ebensburg|city2=Hollidaysburg}}
|notes=}}
{{PAint|exit
|location=Logan Township
|ctdab=Blair
|lspan=3
|mile=30.507
|exit=31
|road={{jctname|state=PA|US-Bus|220|dab1=Altoona|name1=Plank Road|noshield1=yes}}
|notes=Access to [[Logan Valley Mall]]}}
{{PAint|exit
|mile=31.803
|exit=32
|road={{jct|state=PA|to2=to|road|Frankstown Road|PA|36}}
|notes=Access to [[Lakemont Park]] and [[Peoples Natural Gas Field]]}}
{{PAint|exit
|mile=32.921
|exit=33
|road=17th Street
|notes=Access to Logan Town Centre}}
{{PAint|exit
|location=Antis Township
|ctdab=Blair
|lspan=3
|mile=38.521
|exit=39
|road={{jct|state=PA|PA|764|dir1=south|city1=Pinecroft}}
|notes=Northern terminus of PA 764}}
{{PAint|exit
|mile=41.193
|exit=41
|road={{jct|state=PA|PA|865|dir1=north|city1=Bellwood}}
|notes=Southern terminus of PA 865}}
{{PAint|exit
|mile=45.004
|exit=45
|road=[[Tipton, Pennsylvania|Tipton]], [[Grazierville, Pennsylvania|Grazierville]]
|notes=Access via Pleasant Valley Boulevard; access to [[DelGrosso's Amusement Park]]}}
{{PAint|exit
|location=Tyrone
|mile=47.529
|exit=48
|road={{jct|state=PA|PA|453|city1=Tyrone}}
|notes=To [[Pennsylvania Route 550|PA 550]] and [[Huntingdon, Pennsylvania|Huntingdon]]}}
{{PAint|exit
|location=Snyder Township
|ctdab=Blair
|mile=51.592
|exit=52
|road={{jct|state=PA|PA|350|name1=[[U.S. Route 220 Business (Altoona, Pennsylvania)|US&nbsp;220 Bus.]] south|city1=Bald Eagle|city2=Philipsburg|countydab1=Blair|countydab2=Centre}}
|notes=}}
{{PAint|exit
|county=Centre
|cspan=13
|location=Worth Township
|ctdab=Centre
|lspan=2
|mile=61.437
|exit=61
|road=[[Port Matilda, Pennsylvania|Port Matilda]]
|notes=Access via [[U.S. Route 220 Alternate (State College, Pennsylvania)|US&nbsp;220 Alt.]]}}
{{PAint|exit
|mile=62.243
|type=concur
|exit=62
|road={{jct|state=PA|US|322|dir1=west|city1=Philipsburg|countydab1=Centre}}
|notes=Southern end of US 322 concurrency; southbound exit and northbound entrance
}}
{{PAint|exit
|location=Patton Township
|ctdab=Centre
|lspan=3
|mile=68.993
|exit=68
|road=Grays Woods, [[Waddle, Pennsylvania|Waddle]]
|notes=Access via Grays Woods Boulevard/Atherton Street}}
{{PAint|exit
|mile=69.706
|mile2=70.200
|exit=69
|road={{jct|state=PA|US-Bus|322|dab1=State College|dir1=east|name1=Atherton Street|road|Valley Vista Drive|location1=[[Park Forest Village, Pennsylvania|Park Forest]]}}
|notes=Signed for US 322 Bus./Atherton northbound, Valley Vista/Park Forest southbound; western terminus of US 322 Bus.}}
{{PAint|exit
|mile=71.122
|exit=71
|road=[[Toftrees, Pennsylvania|Toftrees]], [[Woodycrest, Pennsylvania|Woodycrest]]
|notes=Access via Waddle Road}}
{{PAint|exit
|location=College Township
|ctdab=
|lspan=2
|mile=73.944
|type=concur
|exit=73
|road={{jct|state=PA|US|322|dir1=east|city1=State College|city2=Lewistown}}
|notes=Northern end of US&nbsp;322 concurrency}}
{{PAint|exit
|mile=75.067
|exit=74
|road=[[Innovation Park (Pennsylvania State University)|Innovation Park]], [[Penn State University]]
|notes=Access via Park Avenue; access to [[Beaver Stadium]] and [[Bryce Jordan Center]]}}
{{PAint|exit
|location=Benner Township
|ctdab=
|lspan=2
|mile=76.484
|exit=76
|road=Shiloh Road
|notes=}}
{{PAint|exit
|mile=78.991
|exit=78
|road={{jct|state=PA|PA|150|city1=Bellefonte}}
|notes=Signed as exits 78A (south) and 78B (north)}}
{{PAint|exit
|location=Spring Township
|ctdab=Centre
|lspan=4
|mile=81.232
|type=incomplete
|exit=80
|road=Harrison Road
|notes=Northbound exit and southbound entrance}}
{{PAint|exit
|mile=81.728
|type=concur
|exit=81
|road={{jct|state=PA|PA|26|dir1=south|to2=to|PA|64|city1=Pleasant Gap}}
|notes=Southern end of PA&nbsp;26 concurrency}}
{{PAint|exit
|mile=83.605
|exit=83
|road={{jct|state=PA|PA|550|city1=Bellefonte|city2=Zion}}
|notes=}}
{{PAint|exit
|mile=85.780
|type=concur
|exit=
|road={{jct|state=PA|US|220|dir1=north|PA|26|dir2=north|to3=yes|I|80}}
|notes=Northern end of US 220/PA 26 concurrency; continuation north
}}
{{jctgap|text=Gap in designation, connection made via [[U.S. Route 220 in Pennsylvania#Major intersections|US 220]]}}
{{PAint|exit
|county=Lycoming
|cspan=11
|location=Williamsport
|lspan=3
|mile=131.67
|type=concur
|exit=
|road={{Jct|state=PA|I|180|dir1=east|US|15|US|220|dir2=south|city1=Montoursville|city2=Lewisburg|city3=Lock Haven}}
|notes=Southern end of US 15 concurrency; current southern terminus; western terminus and exit 29 on I-180
}}
{{PAint|exit
|ctdab=Lycoming
|mile=132.09
|exit=136
|type=incomplete
|road=Third Street
|notes=Northbound exit and entrance
}}
{{PAint|exit
|mile=132.37
|exit=136
|type=incomplete
|road=Fourth Street
|notes=Southbound exit and entrance
}}
{{PAint|exit
|township=Old Lycoming
|ctdab=Lycoming
|mile=132.99
|exit=137
|road=Foy Avenue, High Street, Lycoming Creek Road
|notes=
}}
{{PAint|exit
|township=Lycoming
|ctdab=Lycoming
|lspan=2
|mile=136.34
|exit=140
|road=[[Hepburnville, Pennsylvania|Hepburnville]]
|notes=
}}
{{PAint|exit
|mile=138.90
|exit=143
|type=incomplete
|road={{Jct|state=PA|PA|973|city1=Perryville|city2=Cogan Station}}
|notes=Southbound exit only
}}
{{PAint|exit
|township=Lewis
|ctdab=Lycoming
|mile=144.00
|exit=148
|road={{Jct|state=PA|PA|14|dir1=north|city1=Trout Run|city2=Canton}}
|notes=Southern terminus of PA 14
}}
{{PAint|exit
|location=Cogan House Township
|ctdab=Lycoming
|lspan=3
|mile=148.27
|exit=152
|type=incomplete
|road=[[Cogan House, Pennsylvania|Cogan House]] (Green Mountain Road)<ref name="PAHwys">{{cite web|url=http://www.pahighways.com/us/US15.html|title=U.S. Route 15|last=Kitsko|first=Jeffrey J.|year=2011|publisher=Pennsylvania Highways|access-date=February 25, 2013}}{{unreliable source?|failed=y|date=July 2013}}</ref><ref name="Gazette">{{cite news|title=Route 15 southbound lanes opened|url=http://www.tiogapublishing.com/articles/2009/11/18/news/doc4b0467c06b43f965427341.txt|access-date=February 25, 2013|newspaper=[[Wellsboro, Pennsylvania#Media|The Wellsboro Gazette]]|date=November 18, 2009}}</ref>
|notes=Southbound exit and entrance; connected to Steam Valley Road via [[List of quadrant routes in Lycoming County, Pennsylvania#4000s|State Route 4011]] <!-- As of August 2013, both citations claim this is a "split diamond" interchange. As that term has a specific, and different, meaning in highway design, please avoid using it in any edits of this row. -->
}}
{{PAint|exit
|mile=148.89
|exit=152
|type=incomplete
|road=[[Cogan House, Pennsylvania|Cogan House]] (Steam Valley Road)<ref name="PAHwys"/><ref name="Gazette"/>
|notes=Northbound exit and entrance; access via [[List of quadrant routes in Lycoming County, Pennsylvania#4000s|State Route 4011]] <!-- As of August 2013, both citations claim this is a "split diamond" interchange. As that term has a specific, and different, meaning in highway design, please avoid using it in any edits of this row. -->
}}
{{PAint|exit
|mile=150.90
|exit=155
|road={{Jct|state=PA|PA|184|dir1=west|city1=Steam Valley}}<ref name="PAHwys"/><ref name="Gazette"/>
|notes=Eastern terminus of PA 184
}}
{{PAint|exit
|location=Jackson Township
|ctdab=Lycoming
|mile=153.68
|exit=158
|road={{Jct|state=PA|PA|284|dir1=west|city1=Buttonwood|city2=English Center}}
|notes=Eastern terminus of PA 284
}}
{{PAint|exit
|county=Tioga
|cspan=8
|location=Liberty
|ctdab=Tioga
|lspan=2
|mile=158.81
|exit=162
|road={{Jct|state=PA|PA|414|city1=Liberty|countydab1=Tioga|city2=Morris}}
|notes=
}}
{{PAint|exit
|mile=160.96
|exit=165
|road=[[Sebring, Pennsylvania|Sebring]]
|notes=
}}
{{PAint|exit
|location=Blossburg
|mile=168.08
|exit=172
|road=[[Blossburg, Pennsylvania|Blossburg]]
|notes=
}}
{{PAint|exit
|township=Richmond
|ctdab=Tioga
|mile=175.55
|exit=179
|road={{Jct|state=PA|US-Bus|15|PA|660|dab1=Mansfield|dir1=north|dir2=west|city1=Canoe Camp|city2=Covington}}
|notes=Southern terminus of US 15 Bus.; eastern terminus of PA 660
}}
{{PAint|exit
|location=Mansfield
|mile=177.82
|exit=182
|road={{Jct|state=PA|US|6|city1=Mansfield|city2=Wellsboro}}
|notes=Access to [[Hills Creek State Park]] and [[Mansfield University]]
}}
{{PAint|exit
|township=Richmond
|ctdab=Tioga
|mile=179.16
|exit=183
|type=incomplete
|road={{Jct|state=PA|US-Bus|15|dab1=Mansfield|dir1=south|name1=Main Street}}
|notes=Southbound exit and northbound entrance; northern terminus of US 15 Bus.
}}
{{PAint|exit
|township=Tioga
|ctdab=Tioga
|mile=187.65
|exit=191
|road={{Jct|state=PA|PA|287|city1=Tioga|city2=Tioga Junction}}
|notes=
}}
{{PAint|exit
|township=Lawrence
|ctdab=Tioga
|mile=192.46 
|exit=196
|road={{Jct|state=PA|PA|49|city1=Elkland|city2=Lawrenceville}}
|notes=Access to [[Cowanesque Lake]]
}}
{{jctplace|old
|river=&nbsp;
|river_wide=yes
|mile=194.89
|mile2=0.00
|line=y
|place=[[Pennsylvania]]–[[New York (state)|New York]] state line}}
{{NYint|exit
|sspan=7
|county=Steuben
|cspan=7
|location=Lindley
|lspan=1
|mile=6.36
|exit=6
|road={{jct|state=NY|CR|5|county1=Steuben|city1=Presho}}
}}
{{NYint|exit
|location=Erwin
|lspan=6
|mile=8.16
|exit=8
|road={{jct|state=NY|NY|417|city1=Erwin|city2=Addison|areadab2=village}}
}}
{{NYint|exit
|mile=11.12
|exit=11
|road={{jct|state=NY|NY|417|city1=Gang Mills}}
}}
{{NYint|exit
|mile=11.69
|type=incomplete
|exit=12
|espan=2
|road=Robert Dann Drive ([[County Route 107 (Steuben County, New York)|CR&nbsp;107]])
|notes=No northbound exit
}}
{{NYint
|mile=12.10
|type=incomplete
|road={{jct|state=NY|I|86|dir1=west|NY|17|dir2=west|name2=Southern Tier Expressway|city1=Jamestown|city2=Rochester}}
|notes=Northbound exit and southbound entrance; exit&nbsp;44 on I-86
}}
{{NYint|exit
|type=incomplete
|mile=
|exit=13B
|road={{jct|state=NY|NY|352|dir1=east|NY|415|city1=Riverside|countydab1=Steuben|city2=Downtown Corning}}
|notes=Northbound exit only; NY 415 not signed; western terminus of NY 352
}}
{{NYint|exit
|type=concur
|mile=12.68
|exit=13A
|road={{jct|state=NY|I|86|dir1=east|NY|17|dir2=east|name2=Southern Tier Expressway|city1=Binghamton|city2=Corning|areadab2=city}}<br>{{jct|state=NY|US|15|dir1=ends}}
|notes=Northern terminus; northern terminus of US 15
}}
{{Jctbtm|col=8|keys=concur,incomplete}}

==See also==
*{{Portal-inline|U.S. Roads}}
*{{Portal-inline|New York (state)}}
*{{Portal-inline|Pennsylvania}}
{{Clear}}

==References==
{{Reflist}}

==External links==
{{Commons category|Interstate 99}}
{{Attached KML|display=title,inline}}
* [https://www.aaroads.com/interstate-guide/i-099/ Interstate Guide – I-99]
* [https://www.aaroads.com/guides/i-099-pa/ I-99 in Pennsylvania at AARoads.com]
* [https://www.aaroads.com/guides/i-099-ny/ I-99/US 15 in New York at AARoads.com]
* [http://www.pahighways.com/interstates/I99.html Pennsylvania Highways: Interstate 99] {{Webarchive|url=https://web.archive.org/web/20150924063335/http://www.pahighways.com/interstates/I99.html |date=September 24, 2015 }}
{{NYSR external links|route=99|type=I|nyroutes=yes}}
* [https://www.alpsroads.net/roads/pa/i-99/ Pennsylvania Roads - I-99]

{{interstates}}
{{Authority control}}

{{DEFAULTSORT:Interstate 99}}
[[Category:Interstate Highway System|99]]
[[Category:Interstate Highways in Pennsylvania|099]]
[[Category:Interstate Highways in New York (state)|099]]
[[Category:Bald Eagle Valley|Interstate 99]]
[[Category:Nittany Valley|Interstate 99]]
[[Category:Transportation in Bedford County, Pennsylvania]]
[[Category:Transportation in Blair County, Pennsylvania]]
[[Category:Transportation in Centre County, Pennsylvania]]
[[Category:Transportation in Steuben County, New York]]