D51 connects the A3 motorway Nova Gradià ¡ka interchange to Nova Gradià ¡ka and Poà ¾ega. The road forms two junctions to D38 state road, one in Brestovac, where D38 branches off to Pakrac, and another further east, in Poà ¾ega, where D38 branches off to Pleternica. Between those two junctions D51 and D38 are concurrent. The eastern terminus of the road is near Gradià ¡te, at a junction to D53 state road to Naà ¡ice (to the north) and Slavonski Brod (to the south). The road is long.
The route comprises numerous junctions to county and local roads, as well as a significant number of urban intersections, in segment of the road running through Poà ¾ega.
The road, as well as all other state roads in Croatia, is managed and maintained by Hrvatske ceste, a state-owned company.
The D51 state road currently serves as the principal connection to the city of Poà ¾ega and the A3 motorway, however there are plans to replace it with a new expressway, that is expected to comprise a significantly altered route.
Traffic is regularly counted and reported by Hrvatske ceste, operator of the road.