U.S. Route 1 Business (US 1 Bus.) is a four-lane surface road that provides an alternate route to the Trenton Freeway (US 1) northeast of Trenton in Mercer County, New Jersey. The route is 2.73 mi (4.39 km) long and runs between US 1 in Trenton and Lawrence Township. On the border of Trenton and Lawrence Township, US 1 Bus. intersects the northbound direction of US 206 at the Brunswick Circle. The route was once part of a longer U.S. Route 1 Alternate (US 1 Alt.), which continued southwest through downtown Trenton and into Morrisville, Pennsylvania.