The U.S. Route 1 Bypass of Portsmouth, New Hampshire, was part of a major New Deal project to move U.S. Route 1 traffic away from the congested streets of downtown Portsmouth. It created a second Piscataqua River crossing into Maine via the Interstate (Sarah M. Long) Bridge. Its wide divided lanes and grade separations were the first in the state, earning it the title "New Hampshire’s Most Modern Highway." Today, the U.S. Route 1 Bypass is one of the oldest signed bypasses in the country’s numbered route system.
