[1] It connects the cities of Manila, Makati, Pasay, Taguig, Parañaque, and Muntinlupa.

Between its northern terminus at the intersection with Quirino Avenue (C-3) in Paco district and EDSA (C-4) at Magallanes Interchange in Makati, R-3 is known as Osmeña Highway.

The alignment of West Service Road starts as a zipper lane on the southbound lane of SLEX at the Makati–Pasay boundary, extending as a shoulder onto Sales Interchange, while that of East Service Road commences at Lawton Avenue in Taguig.

However, the R-3 section of West Service Road terminates at its sharp curve next to SLEX's Alabang and South Station Exits.

It stretches from its junction with Montillano Street and Alabang–Zapote Road beneath SLEX's Alabang Viaduct in Alabang to the Muntinlupa Bridge, which crosses the Tunasan River at the city's border with San Pedro, Laguna.