These factors have contributed to a transport system that is highly dependent on private motor vehicles. Several motorways radiating to the north, northwest, southwest and south act as the backbone of the city's road network, with the busiest section of motorway carrying over 200,000 vehicles a day. The use of public transport in Auckland was high until the 1950s but subsequently declined during the second half of the 20th century, before experiencing a strong resurgence from the early 2000s. With the motorway network now largely completed, major efforts are underway to increase public transport use to address Auckland's congestion. Recent efforts have also focused on making cycling a safer and more attractive transport option.