Upon entering Highland Park, Route 27 becomes two-lane Raritan Avenue, intersecting County Route 622 (River Road) and continuing through the downtown area of Highland Park. County Route 514 splits from Route 27 by heading east on Woodbridge Avenue later. Route 27 resumes heading northeast past this intersection as a four-lane road that passes by homes, entering Edison Township, where the name changes to Lincoln Highway. The route continues northeast, intersecting County Route 676 (Suttons Lane/Duclos Lane) and County Route 529 (Plainfield Avenue), then travels through a mix of residences and businesses, briefly becoming a divided highway before intersecting Interstate 287 at a partial interchange with access to southbound Interstate 287 and from northbound Interstate 287. At this interchange, Route 27 sees approximately 14,386 cars a day. Beyond this interchange, Route 27 crosses into Metuchen and becomes two-lane Essex Avenue, which turns to the east and heads through residential areas. The route turns north onto Lake Street and intersects County Route 501 (Amboy Avenue), forming a concurrency with that route. It passes under the Northeast Corridor and comes to Middlesex Avenue, where County Route 501 turns to the left and Route 27 turns to the right to resume its northeast direction.