Route 3 is a state-numbered route in the U.S. state of Massachusetts, maintained by the Massachusetts Department of Transportation (MassDOT). Spanning approximately along a north–south axis, it is inventoried with U.S. Route 3 (US 3) as a single route by the state. The state-numbered Route 3 travels from Bourne in the south to Cambridge in the north, while US 3 continues from Cambridge and crosses the New Hampshire state line in Tyngsborough. Mileposts on US 3 continue from those on the state-numbered Route 3. Route 3 begins in the south as a controlled-access highway at a junction with U.S. Route 6 (US 6) in Bourne. The highway is known as the Pilgrims Highway from Bourne to the Braintree Split at the Braintree–Quincy city line, where Route 3 meets with Interstate 93 (I-93) and U.S. Route 1 (US 1) and the three routes travel concurrently toward Boston as the Southeast Expressway. I-93, US 1, and Route 3 travel through the Central Artery and the O'Neill Tunnel in Downtown Boston, after which point Route 3 exits the concurrency and continues on surface streets. It crosses the Longfellow Bridge on the Boston–Cambridge city line, and transitions into US 3 shortly after an intersection with Route 2A in Cambridge. Route description Massachusetts Route 3 can be said to have three segments: the Pilgrims Highway, the concurrency with Interstate 93, and the section north of I-93 in Boston. Pilgrims Highway is the part of Route 3 that stretches from the intersection with US 6 in Bourne to the junction with Interstate 93 in Braintree. The route is entirely controlled access and ranges from four lanes further south to six further north. Between the towns of Pembroke and Weymouth, the highway is typically composed of four lanes, but is expanded to five during rush hour. During this time, travel is authorized in the breakdown lane of the peak direction. This portion of the route stretches for approximately 43 miles. Route 3 runs concurrently with Interstate 93 and U.S. Route 1 from Exit 7 in Braintree to Exit 18 in Boston. Along this portion of the route, it is known as the Southeast Expressway and is composed of eight lanes. Outside of rush hour, four lanes travel in each direction. However during rush hour, a high-occupancy vehicle lane (HOV) zipper lane is added to the peak direction of travel, making five lanes flow in the peak direction