Tunis is served by an extensive public transportation network made up of buses, a light rail system known as Tunis Metro, and a regional train service connecting the city centre to some of Tunis's northern suburbs.Buses in Tunis are operated by Societe Nationale de Transport Interurbain (SNTRI) and the city is well-covered with more than 200 routes. The Metro system is made up of several lines and covers a substantial part of Tunis and its neighbouring suburbs. Bus, train, and metro fares are relatively inexpensive, but do increase at night. Travellers who want to explore the city at a leisurely pace will find that much of Tunis is accessible on foot.Taxis are easy to find in Tunis and are a comfortable and convenient way to get about. Travellers should always ensure that the driver turns the meter on, so that they do not get overcharged. While it is possible to rent a car in Tunis, drivers should be highly alert and drive defensively as Tunisian drivers are notoriously erratic. For the most part, cars are not necessary for getting around the city. The road conditions are generally good in Tunis. However, pot holes become a problem the further travellers get from the city centre.