Farther east, CR 510 continues into Mendham Borough and becomes Main Street, running through residential neighborhoods.

From this point, the road turns northeast and passes more homes as well as a few businesses, intersecting CR 646 before crossing back into Mendham Township.

The road reaches the commercial downtown and intersects CR 648 before meeting US 202 and the western terminus of Route 124 at the Park Place square.

[1][4] After running through the square, CR 510 leaves the former alignment of Route 24 and continues east onto Morris Street, passing more downtown businesses.

After the one-way pair, CR 510 heads east on four-lane undivided Columbia Turnpike past business parks and residential neighborhoods in Morris Township, eventually gaining a third eastbound lane.

[1][4] Upon crossing the Passaic River, CR 510 enters Livingston in Essex County and becomes four-lane undivided South Orange Avenue as it runs through wooded areas with some business parks.

After an intersection with the southern terminus of the Eisenhower Parkway (CR 609), the route becomes a divided highway again and passes between the Livingston Mall to the north and a branch of Cooperman Barnabas Medical Center to the south.

After crossing CR 607, the road becomes undivided again and passes to the south of residential neighborhoods before running through dense forests.

In this area, the road becomes a divided highway again and crosses the West Branch of the Rahway River into Maplewood.

At this point, the route enters Downtown Newark and turns east onto four-lane Market Street near the Essex County Veterans Courthouse.

CR 510 comes to its eastern terminus at an intersection with Route 21 near Newark Penn Station, with Market Street continuing east under Amtrak's Northeast Corridor to provide access to Raymond Boulevard.