Tobin Bridge - Definition and Overview

The James J. Tobin Memorial Bridge carries U.S. Highway 1 over the Mystic River in Massachusetts between Charlestown and Chelsea. It was constructed in 1948 and 1949. The 36 ft wide roadway has three lanes of traffic on each of two levels with Northbound traffic on the bottom and Southbound on the top.

The bridge is a three-span cantilevered truss bridge 1,525 ft long. The center span is longest at 800 ft and is 115 ft over the river. There are 36 approach spans to the North and 32 to the South. The roadway is seven lanes wide between the shortest (439 ft) span and the center to accommodate a toll plaza.