Medellin has one of the most modern and efficient transportation systems in Colombia. The city has an extensive metro system with two lines covering most of the main areas of the city. The metro is complemented by cable cars, streetcars and buses that provide easy access to the city's hills. The metro and some buses use an integrated ticketing system that makes navigation easier for visitors. Cabs and Uber are widely available, but visitors should use caution when using unlicensed cabs or traveling alone at night.