Interstate 495 overlays the Falmouth Spur, the Maine Turnpike connector between the mainline (I-95) and I-295. The toll road formerly carried I-95 away from the Maine Turnpike to its free route north to Brunswick and Gardiner. There are no exits between the two Interstates, but the east end of the Falmouth Spur does provide access to U.S. 1 in the town of Falmouth.
The Falmouth Spur opened as part of the Maine Turnpike in 1955. It was incorporated as part of the Interstate 95 alignment around Portland in 1956.3 The Maine Turnpike main line north from the west end of the spur to Auburn, Lewiston and West Gardiner was unnumbered.
With Congress passing a law in 1987 that raised the national speed limit from 55 to 65 miles per hour, the state of Maine sought to include all of the Maine Turnpike into the Interstate system. Since the increased speed limit was allowed only on rural Interstate highways, the turnpike outside of I-95 was not applicable. Approved by AASHTO on December 4, 1987, Interstate 495 was established along 50.47 miles of the toll road from Portland to West Gardiner.
Changes for the Maine Interstate system were submitted by Maine to AASHTO, and approved on October 11, 2002. They outlined relocating Interstate 95 westward from the Falmouth Spur and the freeway north from to Brunswick and West Gardiner wholly onto the Maine Turnpike, over what was previously Interstate 495. Interstate 295 was extended northward over former I-95 from Yarmouth to Gardiner. Interstate 495 was then legislatively reapplied to the Falmouth Spur between I-95 and I-295. I-495 was not signed because Maine considered the Falmouth Spur to be just a “ramp”. Sign changes were implemented on January 5, 2004 and completed on January 10th.1
The relocation of Interstate 495 also coincided with a statewide renumbering of all Maine Interstate exits from a sequential-based system to a mile based system. Completed by May 15, 2004, Maine was the first New England state to adopt the national standard.2