Tunis is the starting point from which the main roads and all highways that serve different parts of the country of Tunis originate.  This city has a high density of traffic because vehicle ownership is rising at 7.5% per year.  The capital is home to approximately 40% of the cars in Tunisia, with 700,000 cars on average used in the city per day.  In this context, major road infrastructure (bridges, interchanges, roads, etc..) was initiated in the late 1990s to decongest the main areas of the capital.  The main roads to other Tunisian cities include: Autoroute A1, Tunis-Sfax; Autoroute A3, Tunis-Oued Zarga; and Autoroute A4, Tunis-Bizerte. Also, as part of the major infrastructure project, the city's traffic lights were increased from 5,000 to 7,500.