The upgraded corridor is expected to bolster local economies by attracting business investment and improving clarity for road users.
The designation – effective July 30 – follows decades of modernization and safety improvements.
Montoursville, PA - Today, the Pennsylvania Department of Transportation (PennDOT) announced that a 62-mile section of U.S. 15 in Lycoming and Tioga counties will officially become Interstate 99 (I-99) between Williamsport and the New York state line on Thursday, July 30.
The Federal Highway Administration granted the designation after determining that the corridor meets all federal standards for interstate design, safety, and performance. The newly designated stretch runs from the I-180 interchange in the City of Williamsport, Lycoming County, to the New York/Pennsylvania state line.
This designation marks a major milestone for North Central Pennsylvania. Converting U.S. 15 into I‑99 strengthens the corridor’s infrastructure, supports freight movement, and ensures compliance with modern weight and design requirements.
“This designation from U.S. 15 to I‑99 reflects decades of planning and hard work to make a significant investment in our future. I‑99 strengthens the region’s transportation network by enhancing long-term safety, mobility, and economic opportunity throughout the region,” said PennDOT Secretary Mike Carroll. “The Shapiro Administration will continue to make investments that strengthen our infrastructure, improve quality of life, and open the doors of opportunity for all Pennsylvanians.”
Since 1984, PennDOT has been modernizing U.S. 15 into a continuous, limited-access highway. These improvements were delivered through 34 projects totaling an investment of $480 million, including new alignments, upgrades to shoulders, pavement, access points, and roadway geometry. Updated signage is currently being installed along the 62‑mile corridor and will remain covered until July 30.
The I‑99 designation also improves regional connectivity by linking key routes, including I‑80 and I‑86, making travel more efficient for residents, visitors, and commercial carriers. In the long term, the upgraded corridor is expected to bolster local economies by attracting business investment and improving clarity for road users.
The designation of I-99 will also include changes for companies that hold annual over-dimension hauling permits. Currently on U.S. 15, hauling permits can be issued for divisible loads of certain commodities up to 95,000 pounds. After designation as an interstate, according to federal law, the maximum weight will be reduced to 80,000 pounds for divisible loads if there is no federal exemption for the commodity.
Updates for Hauling Industry
- In accordance with federal law, once designated as I-99, the road’s weight restriction will be reduced to 80,000 pounds for divisible loads.
- Divisible overweight permits will no longer allow travel on the designated section.
- Milk haulers are permitted under federal law to operate overweight on interstates including the future I-99 corridor.
- Haulers will be required to comply with the weight limits or reroute using alternate, approved state routes under their current Annual Network permits.
- After the designation is finalized, the Automated Permit Routing and Analysis System (APRAS) will prevent the issuance of new divisible overweight permits for this corridor.
- Permits for non-divisible oversize or overweight loads will continue to be issued and remain valid for travel along I-99.
Information for road users and haulers is available at www.pa.gov/NewI99.
Travelers can check conditions on major roads by visiting www.511PA.com. 511PA, which is free and available 24 hours a day, provides traffic delay warnings, weather forecasts, traffic speed information and access to more than 1,200 traffic cameras. 511PA is also available through a smartphone application for iPhone and Android devices, by calling 5-1-1, or by following regional X alerts.
Find PennDOT’s planned and active construction projects at www.pa.gov/DOTprojects. Subscribe to PennDOT news and find transportation results in Tioga, Bradford, Lycoming, Sullivan, Union, Snyder, Northumberland, Montour and Columbia counties at www.pa.gov/DOTdistrict3.
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MEDIA CONTACTS: Maggie Baker and Kim Smith at ra-pdd03crc@pa.gov
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