Mostly unsigned in favor of U.S. Highway 90, it runs from the Alabama state line (Perdido River) to Atlantic Beach.

Signage begins at the interchange with Interstate 95 and U.S. Highway 1, where US 1 splits to the south.

About a mile (2 km) before the east end of SR 10, at the east end of the bridge over the Intracoastal Waterway, SR A1A (Mayport Road) joins from the north.

There is an incorrect overhead sign that says the Mayport Road flyover ramp is SR 101, however the SR 101 designation does not begin on Mayport Road for another 2.3 miles (3.6 km).

(Atlantic Boulevard continues several blocks further as a local road to the beach.)