D403 is a state road connecting A7 motorway à  kurinje interchange to the centre of the city of Rijeka, and to the Port of Rijeka West terminal. The road is long.
The D403 state road is scheduled for a reconstruction in order to provide a more efficient connection to the Port of Rijeka, but those plans have been postponed. Currently, D-403 comprises many urban at-grade intersections within the city of Rijeka.
The road, as well as all other state roads in Croatia, is managed and maintained by Hrvatske ceste, state owned company.