This bill mandates the implementation of mileage-based exit numbers on all tier I highways in New Hampshire, with the exception of Interstate 393. The new section, 265:22-a, is added to RSA 265, requiring that exit numbering aligns with the United States Department of Transportation's standards as outlined in the Manual on Uniform Traffic Control Devices. The exit numbers will be determined using the state's department of transportation linear referencing system, and the Department of Transportation is given until the year 2038 to complete the transition from the existing exit numbering system.

The fiscal impact of this bill is projected to begin in FY 2031, with preliminary engineering costs estimated at $132,500 and construction costs around $2,274,000 by FY 2033. Funding for this project is expected to come from federal funds through the Federal Highway Administration, as well as Turnpike Funds for signage changes on the Turnpike System. The bill outlines that the implementation will involve replacing existing exit signs, potentially using overlay panels, and emphasizes that the project will compete for funding with other highway improvement projects in the state.