Transport in Belgium is facilitated with well-developed road, air, rail and water networks. The rail network has 2,950 km (1,830 mi) of electrified tracks.There are 118,414 km (73,579 mi) of roads, among which there are 1,747 km (1,086 mi) of motorways, 13,892 km (8,632 mi) of main roads and 102,775 km (63,861 mi) of other paved roads. There is also a well-developed urban rail network in Brussels, Antwerp and Charleroi. The ports of Antwerp and Bruges-Zeebrugge are two of the biggest seaports in Europe. Brussels Airport is Belgium’s biggest airport.The road network in Belgium is managed by regional authorities, meaning that a road section in Flanders is managed by the Flemish Government, a road section in Brussels by the Brussels government and a road section in Wallonia by the Walloon Government. This explains that road signs in Flanders are written in Dutch, even when referring to a Walloon region, and conversely, which can be confusing for foreigners who do not know the different translations of Flemish or Walloon cities in the other language. The road network in Belgium is made of highways, national (or regional) roads (the secondary network) and communal roads (or streets). Communal roads are managed at the municipal level. There are also a number of orbital roads in Belgium around major cities.