The city council appears to be moving closer to Mayor Mike McGinn’s point of view on replacing the 520 bridge over Lake Washington. McGinn, recall, wants to build light rail (or at least “high-capacity transit,” AKA bus-rapid transit), plus four general-purpose lanes, on 520, which would necessitate changes to the bridge design. The state department of transportation (WSDOT) and state legislature, meanwhile, want to build a six-lane bridge—two HOV lanes, plus four general-purpose lanes. And the city council is currently drafting a letter stating their position on the replacement options. That letter is due April 15, the final day for public comment on the bridge.
Until now. According to Transportation Choices Coalition policy director Bill LaBorde, who spoke this afternoon at a forum on this year’s state legislative session, the council seems poised to “support the [center] lanes [on the bridge] being dedicated to transit only and being adaptable to high-capacity transit—either bus rapid transit or light rail.” Council member Tim Burgess, a member of the transportation committee, confirms that the council is moving toward a push for a more transit-friendly bridge, saying, “the mayor and his consultant [have] shown a way to facilitate making the bridge light-rail ready” or BRT-ready, Burgess said.
What’s at stake? McGinn argues that if WSDOT moves forward with the legislature’s preferred option, it will make it impossible to build light rail later. There are three major changes that would have to be made to include rail on the bridge—two of them relatively minor, one of them less so.
First, the bridge might have to be wider, although it’s probably possible to put rail on a narrower bridge by shrinking the size of the shoulders. Second, the pontoons that support the floating bridge would have to be larger, to carry the extra weight of light rail. Extra pontoons would be added later, but would cost more than simply building bigger pontoons now. Finally, and most dauntingly, a bridge designed for light rail would have to allow the two center light-rail (or BRT) lanes to lift up and head north toward Sound Transit’ light-rail station at Husky Stadium instead of continuing directly west, as the preferred option would do. That’s one of the main reasons McGinn says the state has to consider light rail now, rather than in the future.
Burgess confirms that the council will also likely push for “transit prioritization” on two of the four general-purpose lanes in either 520 scenario. Prioritization, in case it’s not obvious, isn’t the same thing as devoting the lanes to transit or even HOVs; instead, it involves things like allowing buses to jump ahead of cars in line and adding special signals for buses.
