520 is more than just a bridge. It's a major corridor between job centers and growing communities around Lake Washington. Built in 1963, today's 520 bridge is vulnerable to earthquakes and windstorms. In addition, the existing corridor is carrying twice as many vehicles as originally planned and is heavily congested during morning and afternoon commute times. Congestion makes the bridge and its approaches a bottleneck between these economic engines of our region.
When 520 was opened to drivers in 1963, traditional tollbooths were used and it was an immediate success with commuters. This popularity meant that bonds used to pay for the bridge were paid off ahead of schedule. When the last toll was collected in 1979, four times as many vehicles were crossing the bridge each day, compared to when it first opened.
It's time to replace the aging bridge with a safer, more reliable structure. It's time to build a new corridor that moves more people around the lake and provides better access to the highway. Construction of bridge pontoons will begin in 2009.
The new 520 bridge is scheduled to open in 2014. When the corridor is complete, it will include six lanes, with two general-purpose lanes and one carpool lane in each direction, spanning Lake Washington from I-5 in Seattle to just west of I-405 in Bellevue. The bridge will be designed to withstand major earthquakes and windstorms up to 95 mph.
The new 520 will have carpool lanes and increased transit service that will make bus trips more frequent and reliable. It also will have space for walking or riding a bike across the lake, shoulder lanes to keep traffic flowing when something goes wrong, and new interchanges to reduce traffic impacts and improve communities near the corridor.Proposed design for the new 520 bridge.