High Quality Content by WIKIPEDIA articles! Highways in Croatia are the main transport network in Croatia. The primary high-speed motorways are referred to as autoceste and they are defined as roads with at least three lanes in each direction (including hard shoulder) and a speed limit of not less than 80 kilometres per hour (50 mph). They are marked with a special road sign, similar to the road sign depicting an motorway/autoroute/autobahn in other parts of Europe. In Croatia this sign has green background.