The highlight of Croatia's recent infrastructure developments is its rapidly developed motorway network, largely built in the late 1990s and especially in the 2000s (decade). As of December 2020, Croatia had completed  of motorways, connecting Zagreb to most other regions and following various European routes and four Pan-European corridors. The busiest motorways are the A1, connecting Zagreb to Split and the A3, passing east to west through northwest Croatia and Slavonia.