The A6 motorway is a motorway in Croatia spanning 80.2 kilometres (49.8 mi). It connects the nation's capital, Zagreb, via the A1, to the seaport of Rijeka. The motorway forms a major north–south transportation corridor in Croatia and is a part of European route E65 Nagykanizsa–Zagreb–Rijeka–Zadar–Split–Dubrovnik–Podgorica. The A6 motorway route also follows Pan-European corridor Vb.

Highways in Croatia are the main transport network in Croatia. The Croatian classification includes several classes of highways:The main motorway routes are prefixed with an A and accompanied by one or two digits. They are controlled-access highways with tolls using a ticket system. Expressways are toll-free limited-access highways with grade-separated intersections and fast speed limits. They are similar to the motorways, but are not always dual carriageways and may have no emergency lanes. Their speed limit is always lower than the motorways. They either have standalone designations or are parts of non-motorway state routes, such as the D prefixed highways described further below. Roads dedicated for motor vehicles, which is another category of limited-access highways. They usually have multiple lanes and separated carriageways but may have at-grade intersections. This class of roads has no specific numbering convention, only a dedicated traffic sign. State routes or portions thereof may be designated in this manner. An example is Jadranska Avenue in Zagreb, designated as Ž1040, a county road.