D303 is a state road connecting A9 and A8 motorways (Kanfanar interchange) to Rovinj.

The road is 13.5 km long.

[1][2] The road, as well as all other 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 variations between annual (AADT) and summer (ASDT) traffic volumes are attributed to the fact that the road connects A9 motorway carrying substantial tourist traffic to Rovinj, a major summer resort.