The current route was originally legislated in 1911 as part of the Delaware River Drive , a named state highway that was proposed to run from along the Delaware River from Trenton to the New York border in Montague Township . Route 29 was originally defined in 1927 to run from Trenton to Newark . The original route ran from downtown Trenton along State Street and Sanhican Drive . From there , it followed its current alignment to Lambertville , where it followed present @-@ day Route 179 to Ringoes to present @-@ day County Route 514 , which it followed to Woods Tavern . The route turned north on U.S. Route 206 ( also designated Route 31 ) and followed that route to Somerville , where it followed U.S. Route 22 to Newark . The current alignment of Route 29 from Lambertville to Route 12 in Frenchtown was designated Route 29A in 1927 .