Bucharest's public transport system is the largest in Romania and one of the largest in Europe. It is made up of the Bucharest Metro, run by Metrorex, as well as a surface transport system run by STB (''Societatea de Transport București'', previously known as the RATB), which consists of buses, trams, trolleybuses, and light rail. In addition, a private minibus system operates there. , a limit of 10,000 taxicab licences was imposed.