Traveling north from Bedford near the Pennsylvania Turnpike (Interstates 70 & 76) to I-80 near Bellefonte, Interstate 99 represents another growing Interstate corridor. Also known as the Appalachian Thruway and the Bud Shuster Byway, it is the first Interstate highway to have its designation written into law (National Highway Designation Act of 1995). Several other Interstates, including I-66 in Kentucky, I-86 in New York, and I-69 in Texas, have since had their designations written into law.
Ultimately, I-99 will continue north from State College to Lock Haven, Williamsport and along U.S. 15 north to the New York state line by Lawrenceville. The short section of U.S. 15 leading north to Interstate 86 at Painted Post, NY was designated as Interstate 99 on June 27, 2014.1
Speed limits along Interstate 99 were raised to 70 miles per hour (mph) from mile marker 34 in Blair County to Exit 68 in Centre County, and from mile marker zero at the PA Turnpike in Bedford County to Exit 28 in Blair County. Additionally a 49 mile stretch of U.S. 15, from PA 14 in Lycoming County to the New York state line, was increased to 70 mph. PennDOT announced increases on these stretches in May 2016.2
Located east of Interstate 79 and west of Interstate 81, Interstate 99 is the bane of many road enthusiasts who treasure an orderly and sequential numbering system for Interstate highways. The numbering of this highway was determined by Congressman Bud Shuster. He was responsible for writing Interstate 99’s designation into the 1995 National Highway Designation Act. The number “99” violates the standard numbering convention associated with Interstate highways. According to numbering guidelines, I-99 should be hugging the Atlantic coast, not the small Pennsylvania cities of Altoona and State College. Under the orderly system, the lowest numbers are on the West Coast and the highest numbers are on the East Coast. While central Pennsylvania is pretty far east, it is still away from the Atlantic Ocean. Several north-south routes, including Interstates 81, 83, 87, 89, 91, 93, 95 and 97 all lie east of Interstate 99.
High Priority Corridor
Interstate 99 in central Pennsylvania is part of High Priority Corridor 9: Appalachian Thruway Corridor.
Parallel U.S. Routes
Interstate 99 between Bedford and Bellefonte overlaps with U.S. 220 for its entirety, and it will continue along U.S. 220 until reaching U.S. 15 at Williamsport. Interstate 99 is currently cosigned with U.S. 15 in New York, and will overlap or replace U.S. 15 southward to Williamsport when it is finally signed.
The southern terminus of Interstate 99 in Bedford may change in the future, as the highway is part of the Appalachian Thruway/High Priority Corridor 9. Improvements are envisioned for U.S. 220 south to Cumberland, though expansion to Interstate standards are not presently planned.
It is also possible that Interstate 99 could continue north all the way to Rochester via Interstate 390. Although some discussions have considered the possibility of Interstate 83 continuing north to Rochester, it does not appear that will occur due to the large gap of Interstate-standard freeway between Harrisburg and U.S. 15.
The initial section of the U.S. 220 freeway opened south from Bedford Township to U.S. 30 in 1969. The remainder of the route north through Bedford and Blair Counties was built in the 1970s and 1980s.3 $138 million in upgrades to Interstate standards took place along the U.S. 220 freeway north from Bedford to Bald Eagle to 1989.4 Discussions followed in the early 1990s to extend the freeway north 30 miles through Centre County to I-80 near Bellefonte.3 Spearheaded by U.S. Rep. Bud Shuster, R-Everett, the first signs for I-99 were unveiled on December 1, 1995 near the interchange with 17th Street in Altoona. The designation of 35 miles of U.S. 220 between Bedford and Altoona was included in the National Highway System Designation Act signed by President Clinton on November 28, 1995. The bill added 161,000 miles of roads into the National Highway System, which gained priority for federal funding. The law provided $118 million of the estimated $370 million needed at the time to complete the 30-mile I-99 corridor north from Bald Eagle through State College.4
Three sections were proposed in 1995 to complete Interstate 99 north from Bald Eagle to the Bellefonte Bypass (Pennsylvania 26). The 17.5 mile segment from Bald Eagle to U.S. 322, including a bypass of Port Matilda, was estimated to cost $365 million. This section stretches across Skytop Mountain to join the Mount Nitanny Expressway (U.S. 322 around State College).4
The second section involved upgrading U.S. 322 between Scotia Road and Park Avenue Extension, and a relocation of Pennsylvania 26. Also included was a new eight mile alignment linking U.S. 322 at Park Avenue Extension with the Bellefonte Bypass. Expansion of the four-mile Bellefonte Bypass in Spring Township represented the last section at a cost of $180 million.4
An Environmental Impact Statement for I-99 over Bald Eagle Ridge was completed by PennDOT in 1996. The approval of TEA-21 by Congress in 1998 included a two-sentence rider by U.S. Rep. Bud Shuster that eliminated federal oversight of Interstate 99.3 Subsequent approval for Interstate 99 between Bedford and Bald Eagle was approved by AASHTO”s Route Numbering Subcommittee on November 6, 1998.
Land clearing for I-99 commenced in 1999 near Bellefonte and a $39 million contract to build 1.3 miles of new roadway over Bald Eagle Ridge at Skytop was awarded in 2001.3 Meanwhile the eight mile link between State College and Interstate 80 opened to motorists on November 25, 2002. Costing $200 million to build, the segment includes six interchanges.5
North End – Painted Post, NY
South End – Bedford, PA
Branch Routes – 0
Total Mileage – 98.34
Pennsylvania – 85.74
Cities – Bedford, Altoona, Bald Eagle, State College, Bellefonte
New York – 12.60
Cities – Corning
- Junctions –
Source: December 31, 2017 Interstate Route Log and Finders List
I-99 Annual Average Daily Traffic (AADT)
|Location||Vehicles per day|
|Bald Eagle, PA||11,000|
|State College, PA||25,000|
|Jersey Shore, PA||23,000|
|Painted Post, NY||35,800|
Source: Pennsylvania Traffic Volumes 2002 (Penndot)
NYSDOT 2002 Traffic Volume Report
Interstate 99 debuted on the 1995 Official Pennsylvania Highway map from its trumpet interchange with the U.S. 220 Business access road in Bedford to Pennsylvania 350 at Bald Eagle.
Construction of the route west of State College, known as the “Skytop” section, was hampered with delays due to environmental concerns associated with acid rock–sandstone laced with pyrite. Without measures in place to prevent contamination of streams and ground water, crews in 2003 unearthed a million cubic years of the pyrite-laced sandstone, which when exposed to air and water creates sulfuric acid. $82.7 million in work ensued in 2004 to contain the runoff and clean up the site. This delayed work from an anticipated 2006 completion date.3
Following years of delays, the 14-mile link between Bald Eagle and Patton Township opened on December 17, 2007, with the exception of the 1.4-mile section at the acid-rock drainage cleanup site on Skytop Mountain.6
The section between Skytop and State College was finally completed on November 17, 2008, when eight miles of the freeway southbound opened. Total costs for I-99 totaled $702 million. This left the work on the planned high speed interchange joining Interstates 80 and 90. Projected to cost $146 million in 2008, redesign of the exchange was undertaken to avoid excavating too much pyrite.3
The remainder of Interstate 99 in Pennsylvania is a future route with signs proclaiming its extension along U.S. 220 to Lock Haven and Williamsport, then northward along U.S. 15 to the state line at Lawrenceville.
Several decades of construction upgraded U.S. 15 between Williamsport and Painted Post to limited access standards. A new freeway for U.S. 15, from Tioga, Pennsylvania north to Lindley, New York, opened after a ribbon cutting ceremony held on October 1, 2008. The seven mile segment cost $118.7 million.7 See photos of the roadway on John Walter’s site.
Interstate 99 in New York
Within Steuben County and the village of Painted Posted, New York, construction to upgrade the exchange between the Southern Tier Expressway and U.S. 15 (Interstate 99) started in November 2003. The first phase of work involved a $41 million project to bring U.S. 15 up to Interstate standards and to add a diamond interchange with New York 417 (Addison Road / Hamilton Street). The second phase, costing $11 million, rebuilt a two-mile stretch of I-86 by the north end of U.S. 15.8
The final phase of the Painted Post Interchange project added flyovers for the eventual U.S. 15 freeway leading south to Presho and reconstructed Hamilton Street and Robert Dann Drive. The $70 million project commenced in spring 2005 and was scheduled for a fall 2007 completion.9 Delays pushed work to a ribbon cutting ceremony held on the morning of August 13, 2008. Total costs for the three-phase project topped out at $141 million.10
Road construction on the final five mile portion, north from Watson Creek Road at Lindley to Presho, began in August 2012. Taking place as $46 million in ground work wrapped up, the $31 million project included building six bridges.8 Completion took place on October 8, 2013. Total costs to build Interstate 99 in New York were $238 million.11
North End – NY Section – – Painted Post, New York
North End – PA Section – – near Bellefonte, Pennsylvania
Historic Northern Terminus – – Bald Eagle, Pennsylvania
South End – Bedford Township, Pennsylvania
- “Steuben County stretch of Route 15 designated as Interstate 99.” The Leader (Corning, NY), June 27, 2014.
- “Infrastructure – Speed limit extension announced.” Wayne Independent, The (Honesdale, PA) May 7, 2016.
- “Long-awaited Interstate 99 Finished – Road was Long, Rocky and with Stops for Direction.” Centre Daily Times (State College, PA), November 23, 2008.
- “Map Makers Must Draw in New I-99.” Centre Daily Times (State College, PA), December 1, 1995.
- “Drivers Hit Onramps of New I-99.” Centre Daily Times (State College, PA), November 26, 2002.
- “I-99 Link Opens – Connection to Skytop Complete after Years of Setbacks.” Centre Daily Times (State College, PA), December 18, 2007.
- “Work complete on U.S. 15 section.” Leader, The (Corning, NY), October 2, 2008.
- “Final phase of U.S. 15 upgrade underway – I-99 Conversion.” Leader, The (Corning, NY), August 21, 2012.
- “I-86, Rt. 15 interchange under way.” Leader, The (Corning, NY), January 7, 2004.
- “Interchange project prepares for final phase.” Leader, The (Corning, NY), October 22, 2004.
- “Interchange complete.” Leader, The (Corning, NY), August 14, 2008.
- “Route 15 open for business 10-year future I-99 project hits finish line in Lindley – 10-year future I-99 project hits finish line in Lindley.” Leader, The (Corning, NY), October 9, 2013.
- Interstate 86 / Route 15 Interchange Website – Project History,
Page updated January 23, 2017.