Croatia to expand A1 motorway with third lane between Zagreb and Karlovac in €248 million project

A1 motorway (Photo: Woluhar/CC BY-SA 3.0)

ZAGREB, 29 June 2026 – Hrvatske autoceste (HAC) has launched the preliminary consultation process for a major reconstruction and expansion project on the A1 motorway between Zagreb and Karlovac.

The consultation marks the first formal step before the public procurement procedure for one of Croatia’s largest motorway infrastructure projects.

The planned works cover the complete reconstruction of the 39-kilometre section and the addition of a third traffic lane in both directions on one of the country’s busiest and most important motorway routes.

The €248 million project also includes the construction of three new interchanges at Stupnik, Ašpergeri and Selce (Karlovac), the reconstruction of the Jastrebarsko interchange, and the removal and replacement of existing overpasses crossing the motorway.

According to HAC, expanding the motorway will significantly increase traffic capacity, particularly during the busy summer tourist season, while also improving local accessibility and road connections.

The project is also expected to enhance road safety, reduce congestion and improve overall traffic flow on the A1 corridor, which links northern and southern Croatia.

Environmental benefits are also planned, including lower traffic noise levels and better protection of motorway infrastructure through more effective monitoring and control of heavy vehicles.

Construction is scheduled to begin during 2027.

During the works, temporary traffic management measures will be introduced. Two narrowed lanes will remain open in each direction, with reduced speed limits to maintain traffic flow while ensuring safety.

The preliminary consultation with interested economic operators is being carried out in accordance with Croatia’s Public Procurement Act and is a mandatory stage before the official public tender is launched. Once the consultation is completed, the formal procurement process will begin.