The D8 state road is the Croatian section of the Adriatic Highway, running from the Slovenian border at Pasjak via Rijeka, Senj, Zadar, Šibenik, Split, Opuzen and Dubrovnik to the border with Montenegro at Karasovići. Most of the D8 state road remains single carriageway, though with some dual carriageway stretches. The total length of the road through Croatia is. Until recently, the road was the primary route connecting the Adriatic coastal parts of Croatia. Since the 2000s, multilane motorways have taken over most of its traffic, and yet more motorways are still being built along the coast. The motorways parallel to the road are the A7, A6 and A1, sections of the proposed Adriatic–Ionian motorway. Since the D8 closely follows the well-indented Croatian coastline, travel is considerably longer and less safe compared to the motorways because of numerous blind curves and at-grade intersections. The D8 is still popular as an alternative to the tolled motorways, so the road carries fairly constant traffic during most of the year. The traffic intensifies in the summer, because of substantial traffic to tourist destinations. The section from Rijeka to Senj experiences heavy traffic in particular because many motorists are unwilling to take the longer route along A6 and A1. This problem used to be exacerbated before 2009 when A6 still had slow semi-highway parts on the Rijeka–Bosiljevo route. This section will remain congested at peak times until eventual completion of the A7 motorway between Rupa and Žuta Lokva. Since the parallel A1 motorway ends near Ploče, southbound A1 traffic generally switches to the D8 state road. after Ploče, the D8 road terminates at the Klek border crossing to Bosnia and Herzegovina, as the Adriatic Highway route runs across a tiny strip of Bosnia and Herzegovina territory around the town of Neum. As the route reenters Croatia at Zaton Doli border crossing the D8 state road resumes, running to Dubrovnik along the coastline. East of Dubrovnik the road passes by Dubrovnik Airport and reaches the border with Montenegro at the Karasovići border crossing. There are official plans to build an expressway bypassing Neum in Bosnia and Herzegovina entirely via a series of tunnels and bridges, Pelješac Bridge being the most notable. The route would diverge from the current D8 route south of Ploče, cross the bridge to the Pelješac peninsula, form a junction to the D414 state road and rejoin the present D8 route near Doli. The expressway is to be tolled. So far no official road number has been assigned to the planned route, although construction of the Pelješac Bridge was started. It is also possible that the D8 designation will be transferred from the bypassed D8 section to the expressway. The D8 is the longest state road in Croatia at. The road, as well as all other state roads in Croatia, is managed and maintained by Hrvatske ceste, a state-owned company.
Traffic is regularly counted and reported by Hrvatske Ceste. Significant variations between annual and summer traffic volumes are attributed to the fact that the road carries substantial tourist traffic. Traffic volume on the D8 state road varies greatly, as the road runs through areas of more or less developed tourist industry. Furthermore, the road runs through or near a number of major Croatian cities, such as Rijeka, Zadar and Split, which add to the traffic volume significantly. Thus the most congested section of the D8 state road is in the city of Split, between Solin and Stobreč, where the greatest AADT figures are regularly recorded, far exceeding comparable figures of the busiest motorway sections in Croatia. Conversely, the lowest traffic volume on the D8 road is observed near Karlobag due to comparatively less developed tourism and the absence of major cities in the area. The AADT recorded on the D8 road observed in Split is nearly 50 times greater than in Karlobag. Note: All the traffic counting sites are located along the D8 road.
Major intersections
Listed settlements contain additional intersections with local and/or non-categorized roads. The intersections are at-grade except where otherwise noted.
