 In 1922, Connecticut took over the maintenance of the main through routes and State Highway 112 was established, incorporating the old turnpike alignment from Guilford to Durham and extending north beyond Durham into Middletown (along modern Route 17).In the 1932 state highway renumbering, Route 77 was created from the portion of old Highway 112 south of Durham center.The portion north of Durham center became part of Route 15 (now Route 17).