The city has, as of the beginning of the 21st century, a public transportation system developed under the management of the Société des transports de Tunis (STT). In addition to some 200 bus routes, the first light rail line opened in 1985. The Métro léger de Tunis network has extended gradually since then to reach the suburbs. The capital is also linked to its northern suburbs by the railway line that crosses the lake, dividing the lake into two.