The Vasco da Gama Bridge is a cable-stayed bridge flanked by viaducts and rangeviews that spans the Tagus River near Lisbon, capital of Portugal. It is the longest bridge in Europe (including viaducts), with a total length of 17.2 km (10.7 mi), including 0.829 km (0.5 mi) for the main bridge, 11.5 km (7.1 mi) in viaducts, and 4.8 km (3.0 mi) in dedicated access roads. Its purpose is to alleviate the congestion on Lisbon's other bridge (25 de Abril Bridge), and to join previously unconnected motorways radiating from Lisbon.
The bridge was opened to traffic on 29 March 1998, 18 months after construction first began, just in time for Expo 98, the World's Fair that celebrated the 500th anniversary of the discovery by Vasco da Gama of the sea route from Europe to India.
The bridge carries six road lanes, with a speed limit of 120 km/h (75 mph), the same as motorways, except on one section which is limited to 100 km/h (60 mph). On windy, rainy, and foggy days, the speed limit is reduced to 90 km/h (56 mph). The number of road lanes will be enlarged to eight when traffic reaches a daily average of 52,000.
The project was split in four parts, each one built by a different company, and supervised by an independent consortium. There were up to 3,300 workers simultaneously on the project, which took 18 months of preparation and another 18 months of construction.