The A9 motorway is a north–south motorway in Croatia, with a length of 78.3 kilometres. Beginning in Pula, the largest city on the Istrian peninsula, it runs north to the Croatian motorway and expressway network at the Kanfanar interchange. Here it meets the A8 motorway, forming the Istrian Y road system. The A9 continues north from here to the Kaštel and Plovanija border crossings into Slovenia. The motorway represents a significant north–south transportation corridor in Croatia and is a part of the European route E751. The motorway's national significance is reflected in the positive economic impact on the cities and towns it connects, as well as its importance to tourism in Croatia. Importance of the motorway for tourism is particularly high during summer tourist seasons, when traffic volume increases by more than 80%.

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.