Controlled-access highways in Poland are part of the national roads network and they are divided into motorways and expressways. Both types of highways feature grade-separated interchanges with all other roads, emergency lanes, feeder lanes, wildlife crossings and dedicated roadside rest areas. Motorways differ from expressways in their technical parameters like designated speed, permitted road curvature, lane widths or minimal distances between interchanges. Moreover, expressways might have single-carriageway sections in case of low traffic densities.