D0 motorway (Czech Republic)

D0 motorway (Dálnice D0) or Prague Ring Road (Pražský okruh), also called the outer ring road, is a motorway in the Czech Republic. It is an outer ring of Prague and its first segment was opened in the 1980s. There is also an inner Prague Municipal Ring Road, which is still under construction as well.

40 km, from the planned length 80 km, are in operation. Two disjunct sections are opened to the public, one going all the way from the Ruzyně Airport to the interchange with the D1 highway, the other one being a 5 km road on the eastern border of Prague. A section connecting these two segments is to be built next. Other segments under preparation include a bridge over the Vltava river near Suchdol. It was formerly called R1 expressway (Rychlostní silnice R1).