 The Zagreb–Split motorway, now the A1 motorway, was one of three routes defined by the Parliament of the Socialist Republic of Croatia on 5 March 1971, as priority transport routes of Croatia that were to be developed as motorways.Originally the motorway was designed to follow a route from Zagreb to Bihać (Bosnia and Herzegovina) and then to Split via Knin.The government of Bosnia and Herzegovina issued its approval for the route in Bihać region in the same year.