It is known as Old Bridge-Matawan Road for its entire length in Old Bridge where it interchanges with US 9, and then continues several more miles to the Old Bridge/Matawan border, where it enters Monmouth County.

In Keyport, CR 516 has a grade-separated interchange with Route 35; part of this 1965 alignment follows West 4th Street before rejoining Maple Place and following it to Green Grove Avenue.

[5] Another 0.3-mile-long (0.48 km) spur consists of Green Grove Avenue between Maple Place and 1st Street (CR 6).

Before the county route system, the road from Keyport to Atlantic Highlands was part of the Jersey Coast Way, which ran from the Staten Island Ferry to Cape May.

From the Monmouth County line it absorbed part of CR 6 through Matawan and Aberdeen to Keyport.

CR 516 Alternate was previously the designation of Broad Street in Matawan, but was never signed differently than the parent route.