D504 is a state road in Lika region of Croatia connecting the D1 state road to Ličko Petrovo Selo border crossing to Bihać, Bosnia and Herzegovina[1] via the D217 state road.

The road is 9.9 km (6.2 mi) long.

[2] The D504, like all state roads in Croatia, is managed and maintained by Hrvatske ceste, state owned company.

[3] Traffic is regularly counted and reported by Hrvatske ceste, operator of the road.

[4] Substantial seasonal variations of the traffic volume is attributed to summer tourist traffic.