Pennsylvania’s U.S 15 to become I-99 with reduced maximum weight for trucks

This month, a 62-mile section of highway spanning two Pennsylvania counties will be designated as an interstate.

On July 30, 2026, U.S. 15 between the I-180 interchange in the City of Williamsport and the New York/Pennsylvania state line will become I-99.

Currently, truckers can obtain permits for U.S. 15 for divisible loads of certain commodities up to 95,000 pounds. Once the roadway becomes part of the federal interstate system, the maximum weight will be reduced to 80,000 pounds for divisible loads if there is no federal exemption for the commodity, according to the Pennsylvania Department of Transportation (PennDOT).

PennDOT notes that milk haulers are permitted under federal law to operate overweight on interstates, including the future I-99 corridor.

PennDOT received approval from the Federal Highway Administration to designate U.S. 15 as I-99 after the agency determined that the roadway meets all federal standards for interstate design, safety, and performance.

PennDOT listed the following benefits for converting U.S. 15 into an interstate:

• Improve highway consistency and driver clarity. The route will be part of a continuous, signed Interstate corridor from Bedford to the New York border, making navigation simpler for both freight and passenger traffic.
• Enhance economic opportunity. Interstate designation promotes regional commerce by strengthening north–south connections to I-80 and I-86, encouraging business investment and growth throughout north-central Pennsylvania.
• Strengthen freight movement safety and compliance. Converting the route to Interstate status aligns it with federal weight-limit rules and modern design expectations, protecting pavement and bridge assets and ensuring fair, consistent permit enforcement statewide.