D9 is a state road connecting Metković border crossing to Čapljina and Mostar, Bosnia and Herzegovina and D8 state road south of Opuzen.

[maps 1] The road is 10.9 km (6.8 mi) long.

[1] The road also provides connection to A1 motorway Ploče interchange and A10 motorway Kula Norinska interchange via the D62 state road and cities of Metković and Opuzen.

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

[3] Substantial variations between annual (AADT) and summer (ASDT) traffic volumes are attributed to the fact that the road carries substantial tourist traffic.