Warsaw is a considerable transport hub linking Western, Central and Eastern Europe. The city has a good network of buses and a continuously expanding perpendicular metro running north to south and east to west. The tram system is one of the biggest in Europe, with a total length of . As a result of increased foreign investment, economic growth and EU funding, the city has undertaken the construction of new roads, flyovers and bridges. The supervising body is the City Roads Authority (ZDM – ''Zarząd Dróg Miejskich'').