Adriatic–Ionian motorway or Trieste-Kalamata Highway or the Blue Corridor, is a future motorway that will stretch along the entire eastern shore of the Adriatic and Ionian seas, spanning the western coast of the Balkan peninsula from Italy in the north through Slovenia, Croatia, Montenegro, Albania to Greece in the south.

The A1 motorway is the longest motorway in Croatia, spanning 476.3 kilometers (296.0 mi). As it connects the nation's capital Zagreb to the second largest city Split, the motorway represents a major north–south transportation corridor in Croatia and a significant part of the Adriatic–Ionian motorway. Apart from Zagreb and Split, the A1 motorway runs near a number of major Croatian cities, provides access to several national parks or nature parks, world heritage sites, and numerous resorts, especially along the Adriatic Coast. National significance of the motorway is reflected through its positive economic impact on the cities and towns it connects as well as its importance to tourism in Croatia.