The Braintree Split is the major interchange of Interstate 93 (I-93), U.S. Route 1 (US 1), and Route 3 in the South Shore of Massachusetts, on the city line between Braintree and Quincy. Traveling northbound, the routes merge into a three-way concurrency towards Boston. Traveling southbound, they divide into the concurrent I-93 and US 1 towards southeastern Massachusetts, and Route 3 towards Cape Cod.