Interstate 99 (I-99) is an
Interstate Highway
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. T ...
in the United States with two segments: one located in central
Pennsylvania
Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Ma ...
, and the other in southern
New York.
The southern terminus of the route is near exit 146 of the
Pennsylvania Turnpike (
I-70/
I-76) north of
Bedford
Bedford is a market town in Bedfordshire, England. At the 2011 Census, the population of the Bedford built-up area (including Biddenham and Kempston) was 106,940, making it the second-largest settlement in Bedfordshire, behind Luton, whilst ...
, where the road continues south as
U.S. Route 220 (US 220). The northern terminus of the Pennsylvania segment is near exit 161 of
I-80 near
Bellefonte. The New York segment follows
US 15 from the Pennsylvania–New York border to an interchange with
I-86 in
Corning. Within Pennsylvania, I-99 passes through
Altoona and
State College State College is a city in central Pennsylvania, United States.
State College may also refer to:
Related to State College, Pennsylvania
* State College Area School District, a school district serving State College
* State College Area High School ...
—the latter home to
Pennsylvania State University
The Pennsylvania State University (Penn State or PSU) is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High School of Pennsylvania, Penn State becam ...
—and is entirely
concurrent with US 220. Long-term plans call for the two segments of I-99 to be connected using portions of I-80, US 220, and
US 15 through Pennsylvania.
Unlike most Interstate Highway numbers, which were assigned by the
(AASHTO) to fit into a grid, I-99's number was written into Section 332 of the
National Highway System Designation Act of 1995 by
Bud Shuster, then-chair of the
U.S. House Committee on Transportation and Infrastructure
The U.S. House Committee on Transportation and Infrastructure is a standing committee of the United States House of Representatives.
History
The Committee on Transportation and Infrastructure was formerly known as the Committee on Public Works a ...
, the bill's sponsor, and the representative of the district through which the highway runs. I-99 violates the AASHTO numbering convention associated with Interstate Highways, as it should lie to the east of
I-97
Interstate 97 (I-97) is a part of the Interstate Highway System that runs entirely within Anne Arundel County, Maryland. The Interstate runs from U.S. Route 50 (US 50)/US 301 in Parole near Annapolis north to I-695 and I-895 in Brooklyn ...
but instead lies east of
I-79 and west of
I-81.
Route description
Pennsylvania
, -
, PA
, 85.78
, 138.05
, -
, NY
, 13.08
, 21.05
, -
,
, 98.86
, 159.10
I-99 begins at an indirect interchange with US 220 and the
Pennsylvania Turnpike (
I-70/
I-76) north of
Bedford
Bedford is a market town in Bedfordshire, England. At the 2011 Census, the population of the Bedford built-up area (including Biddenham and Kempston) was 106,940, making it the second-largest settlement in Bedfordshire, behind Luton, whilst ...
. It begins
concurrent with
US 220, which continues south from the interchange toward the
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; ...
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
US 220 Business. North of the turnpike junction, the
limited-access highway becomes the Bud Shuster Highway as it heads through a rural portion of
Bedford County. It connects to
Pennsylvania Route 56 (PA 56) just west of the
Bedford County Airport
Bedford County Airport is a public airport in Bedford County, Pennsylvania. It is owned by the Bedford County Airport Authority and is five miles north of the borough of Bedford, Pennsylvania. It opened in 1994.
Most U.S. airports use the same ...
at exit 3 and
PA 869 at exit 7 before crossing into
Blair County
Blair County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 122,822. Its county seat is Hollidaysburg. The county was created on February 26, 1846, from parts of Huntingdon and Bedford counties.
Blai ...
. Here, it meets
PA 164 north of
East Freedom at exit 23 prior to entering the
Altoona area.
In
Hollidaysburg, a borough south of the city, I-99 and US 220 connect to
US 22 at exit 28, a large modified
trumpet interchange. This junction allows travelers to head west towards
Ebensburg,
Johnstown, and
Pittsburgh
Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...
. The freeway continues to Altoona itself, where it indirectly connects to
PA 36 via exit 32. Unlike the original routing of US 220 which goes through the city center, I-99 and US 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,
PA 764 joins the old alignment of US 220 and parallels I-99 north for toward
Bellwood. PA 764 leaves old US 220 about south of Bellwood, however, and terminates at I-99 exit 39. Bellwood itself is served by exit 41, which leads to
PA 865.

The highway veers northeastward from Bellwood to serve the borough of
Tyrone, located at the junction of old US 220 and
PA 453. Access to the borough is made by way of exit 48, which serves PA 453. Past Tyrone, I-99 and US 220 head through sparsely populated areas of Blair and
Centre counties. For this reason, only three exits exist between Tyrone and
State College State College is a city in central Pennsylvania, United States.
State College may also refer to:
Related to State College, Pennsylvania
* State College Area School District, a school district serving State College
* State College Area High School ...
: exit 52, serving
PA 350 and the small community of
Bald Eagle
The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same nich ...
, and exits 61 and 62, which connect to
US 322 and the borough of
Port Matilda. Here, US 322 joins I-99 and US 220 and follows them eastward to the State College area.
At exit 68 (
US 322 Business), I-99 merges into the Mount Nittany Expressway, an older, northerly bypass of State College. I-99, US 220, and US 322 follow the expressway to the Mount Nittany Interchange, a
directional T interchange located on the northern fringe of the
Pennsylvania State University
The Pennsylvania State University (Penn State or PSU) is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High School of Pennsylvania, Penn State becam ...
campus.
Beaver Stadium, the home of the
Penn State Nittany Lions football team, is visible from I-99 at this point. US 322 continues east through the interchange to follow the Mount Nittany Expressway while I-99 and US 220 split from US 322 and head northeastward toward
Pleasant Gap, which I-99 connects to via exit 81 and
PA 26. At this point, PA 26 joins the freeway and follows it to
Bellefonte, served by exit 83 and
PA 550. The southern segment of I-99 ends about later at an intersection with Musser Lane though the divided highway continues northeast to an interchange with
I-80, where PA 26 continues north and US 220 joins I-80 east.
New York

The northern segment of I-99 is entirely concurrent with
US 15, and starts at the Pennsylvania-
New York border north of
Lawrenceville, Pennsylvania
Lawrenceville is a borough in Tioga County, Pennsylvania. The population was 690 at the 2020 census.
Geography
Lawrenceville is located at (41.996564, -77.125159). It is at the intersection of Pennsylvania Route 287 and Pennsylvania Route 49. ...
. A four-lane freeway through the
Steuben County town of
Lindley, I-99 crosses through a rock cut, making a large bend to the north and bypassing the hamlet of
Presho. The freeway enters a
partial cloverleaf interchange with
CR 5 (Smith Road). After CR 5, I-99 turns northeast through the town of
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
NY 417 (Addison Road). After NY 417, it then turns alongside
Norfolk Southern Railway
The Norfolk Southern Railway is a Class I freight railroad in the United States formed in 1982 with the merger of Norfolk and Western Railway and Southern Railway. With headquarters in Atlanta, the company operates 19,420 route miles (3 ...
's
Southern Tier Line (former
Erie Railroad
The Erie Railroad was a railroad that operated in the northeastern United States, originally connecting New York City — more specifically Jersey City, New Jersey, where Erie's Pavonia Terminal, long demolished, used to stand — with Lake ...
main line). Now paralleling the tracks and NY 417, I-99/US 15 crosses through Erwin, entering exit 11, which connects to NY 417 once again, next to Gang Mills Yard,
the site of the former
Painted Post
Painted Post is a village in Steuben County, New York. The village is in the town of Erwin, west of the city of Corning. The population was 1,809 at the 2010 census. The name comes from a Seneca carved post found by explorers at the junction o ...
station.

After Gang Mills Yard, I-99 crosses through the
Gang Mills section of Erwin, entering a large interchange at the northern end of the neighborhood. Signed exit 12, this interchange serves
CR 107 (Robert Dann Drive) via NY 417. After CR 107, I-99 enters a large interchange that utilizes several flyover ramps between I-99, US 15,
I-86, and
NY 17 (the
Southern Tier Expressway). Ramps are also present, connecting to
NY 352. This interchange serves as the northern terminus of both I-99 and US 15.
History
Origins

Corridor O of the
Appalachian Development Highway System was assigned in 1965, running from
Cumberland, Maryland (
Corridor E, now
I-68) to Bellefonte (
I-80) along
US 220. The portion in
Pennsylvania
Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Ma ...
, from
Bedford
Bedford is a market town in Bedfordshire, England. At the 2011 Census, the population of the Bedford built-up area (including Biddenham and Kempston) was 106,940, making it the second-largest settlement in Bedfordshire, behind Luton, whilst ...
north to
Bald Eagle
The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies the same nich ...
, was upgraded to a
freeway
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms ...
in stages from the 1960s to the 1990s. The first section, from
US 30 in Bedford to
PA 56 near
Cessna, opened in the latter half of the 1960s.
Two more sections—from PA 56 north to modern exit 15 in
Blair County
Blair County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 122,822. Its county seat is Hollidaysburg. The county was created on February 26, 1846, from parts of Huntingdon and Bedford counties.
Blai ...
and from
Charlottsville (exit 45) to Bald Eagle—were completed in the 1970s.
The portion between exit 15 and
Altoona (exit 33) was finished in the 1980s
while the segment between modern exits 33 and 45 was opened by 1997.
In 1991, the
Intermodal Surface Transportation Efficiency Act (ISTEA) was signed into law.
It included a number of High Priority Corridors, one of which—Corridor 9—ran along US 220 from Bedford to
Williamsport, and then north on
US 15 to
Corning, New York.
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)
orridor 9is designated as Interstate Route I-99."
This was the first Interstate Highway number to be written into law rather than to be assigned by
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 to
McKeesport. I-99 violates the AASHTO numbering convention associated with Interstate Highways, since it lies east of
I-79 but west of
I-81.
Designation and Bald Eagle Ridge
On November 6, 1998, AASHTO formally approved the I-99 designation, which initially extended from the
Pennsylvania Turnpike in Bedford to
PA 350 in Bald Eagle.
In 2002, plans were set in motion to extend I-99 northeast from Bald Eagle to
State College State College is a city in central Pennsylvania, United States.
State College may also refer to:
Related to State College, Pennsylvania
* State College Area School District, a school district serving State College
* State College Area High School ...
via
Port Matilda.
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 Ridge, the
Pennsylvania Department of Transportation
The Pennsylvania Department of Transportation (PennDOT) oversees transportation issues in the Commonwealth of Pennsylvania. The administrator of PennDOT is the Pennsylvania Secretary of Transportation, currently Yassmin Gramian. Presently, Pe ...
(PennDOT) and valley residents favored a routing that took the freeway above the valley and along the side of the ridge. Farther north, the widening of Skytop, the mountain cut that
US 322 uses to traverse Bald Eagle Ridge, resulted in the exposure of acidic
pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue giv ...
rock in 2003.

Work on the segment ceased one year later
as PennDOT attempted to stop the flow of acidic runoff from the site. The state remedied the situation by removing of pyrite and replacing it with a mix of
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...
and fill, a process that took two years and cost $83 million.
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, 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.
In all, the Bald Eagle–State College section of I-99 cost $631 million to construct.
I-99 was extended northeastward to meet
I-80 northeast of
Bellefonte following the completion of the Bald Eagle–State College segment. The connection was made by way of the pre-existing Mount Nittany Expressway and another, unnamed limited-access highway connecting the State College bypass to the Bellefonte area.
The portion of the latter highway north of the
PA 26 interchange was originally built in the 1970s as a
two-lane freeway connecting
Pleasant Gap to I-80. At the time, it was designated solely as PA 26.
It was widened to four lanes in 1997. The piece connecting the PA 26 freeway to the Mount Nittany Expressway was completed in 2002.
US 220 was rerouted via US 322 and the new road, and the old alignment of US 220 north of US 322 was designated
US 220 Alternate on May 30, 2003.
Further north, one short segment of two-lane highway remained between Lawrenceville, PA and Presho, NY, almost entirely within New York. In the early 2010's, five miles of new freeway was constructed to connect the existing freeway segments. This provided through traffic with a continuous freeway from Williamsport, PA to Corning, NY, and removed traffic from the overburdened two-lane section of US 15, which was retired to county route status as Steuben County Route 115. On June 27, 2014, New York Governor
Andrew Cuomo
Andrew Mark Cuomo ( ; ; born December 6, 1957) is an American lawyer and politician who served as the 56th governor of New York from 2011 to 2021. A member of the Democratic Party, he was elected to the same position that his father, Mario Cu ...
announced that the interstate-grade US 15 freeway from the Pennsylvania border to I-86 in Corning was officially signed as I-99.
[
]
Future
Though there is no specific date for completion, long-term plans call for the two segments of I-99 to be connected via US 220 from Bellefonte to Williamsport, running concurrent with I-80 as US 220 currently does, and continue northward along US 15 from Williamsport to the New York border. The entire portion of US 15 involved has been upgraded to 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. 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". Some of this section of road has also received exit number designations.
PennDOT has plans to build a high-speed interchange connecting I-99 to I-80 near Bellefonte. The new interchange will eliminate local access between PA 26 (Jacksonville Road) and I-80, which will be provided by a new exit to the east. The first phase of the project built the local access interchange between PA 26 and I-80.[ Bidding on the local access interchange began on April 23, 2020 and construction began on July 27, 2020. The local access interchange was opened to traffic on November 10, 2022, with a ribbon-cutting ceremony held. The local access interchange between PA 26 and I-80 was funded by a $34 million federal grant. The second phase of the project will make improvements to Jacksonville Road between the new interchange and the junction between I-80 along with building the high-speed interchange between I-80 and I-99. Bidding on the second phase is 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.]
During a 2002 task force meeting for I-99, it was suggested that I-390, which extends north from I-86 west of the I-86/I-99 junction near Corning and which crosses I-90 and terminates in the greater 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 15, originally extended to Rochester. No official moves to accomplish this have been taken.
Exit list
See also
*
*
*
References
External links
Interstate Guide - I-99
I-99 in Pennsylvania at AARoads.com
I-99/US 15 in New York at AARoads.com
Pennsylvania Roads - I-99
{{DEFAULTSORT:Interstate 99
99
099
99 may refer to:
* 99 (number), the natural number following 98 and preceding 100
* one of the years 99 BC, AD 99, 1999, 2099, etc.
Art, entertainment, and media
* '' The 99'', a comic series based on Islamic culture
Film, television and radio ...
099
99 may refer to:
* 99 (number), the natural number following 98 and preceding 100
* one of the years 99 BC, AD 99, 1999, 2099, etc.
Art, entertainment, and media
* '' The 99'', a comic series based on Islamic culture
Film, television and radio ...
Interstate 99
Interstate 99
Transportation in Bedford County, Pennsylvania
Transportation in Blair County, Pennsylvania