EAST BAY EXPRESS– Fantasies
of bicycling and walking between San Francisco and Oakland along the
Bay Bridge are slowly inching their way toward reality. The Bay Bridge Bikeway Project, a joint venture between the Metropolitan Transportation Commission and Caltrans,
hopes to allow bicyclists and pedestrians to travel between the two
cities along the full span of the bridge. If approved, MTC officials
said it would be the largest engineering feat of its kind in history.
The forthcoming completion of the eastern span already includes a fifteen-and-a-half-foot-wide elevated pathway on the south side to allow bicyclists and pedestrians to ride and walk to Yerba Buena Island. The pathway won’t extend to the western span, which would allow folks to make it to San Francisco. But that may change, as the MTC is currently working on a project study report for release early next year that officials hope will jump-start planning for a western pathway and put the project on the radar for funding.
The MTC study revisits and builds upon data gathered for a 2001 Caltrans study, which examined the feasibility of adding cantilevers on both sides of the western span’s upper deck to accommodate bike and pedestrian traffic. However, a decade’s worth of development changes on the San Francisco touchdown side of the bridge’s potential bikeway have caused the MTC to rethink the designs for the approach into the city as well as the cantilevers themselves, according to MTC Project Manager Peter Lee, who’s in charge of the study.
According to Lee, the 2001 study had the bikeway’s San Francisco touchdown in the Rincon Hill area, but the area has changed so dramatically over the last decade that the designers and engineers are now looking into a single pathway along one side of the bridge’s upper deck instead of the proposed two — an alternative that may prove to be cheaper as well. Lee says the initial feasibility study also didn’t include enough analytical work on the approaches and touchdowns, which prompted the current project study report.
The western suspension bridge is lifted 220 feet above the water, which makes the touchdowns even more challenging in San Francisco, said East Bay Bicycle Coalition Project Manager Dave Campbell. “How do you get people down from that height and get them down safely?” he asked.
The biggest structural challenge of the $1.2 million MTC study, Lee said, is figuring out how to add a structure alongside the bridge between San Francisco and Yerba Buena Island. He pondered how to manage staging equipment for the construction as well as how to handle traffic delays. “No one’s ever done this before,” he said. “Typically, people just build a new bridge.”
However, Lee said, building an unattached bikeway alongside the existing 2,310-foot western span is not an option, mostly because it would distort the bridge’s image. In 2001, preliminary funding priced the bikeway project on the western span at between $160 and $390 million for two alternatives that varied only slightly in design. The cheaper of the two involved adding two pathways on both sides of the span while using suspender cables to lift them. The more expensive alternative suggested adding two pathways but replacing the lower concrete deck with lightweight steel to minimize refraction. Today, Lee estimates that the project will cost half a billion to a billion dollars. “Half a billion dollars — that’s a whole bridge somewhere else,” Lee said.
But funding is truly the biggest obstacle. While there is currently no source of funding for the western bike pathway, the MTC and Caltrans are eyeing increased bridge toll revenue as one way to help fund the project, says MTC spokesman John Goodwin. “There’s no cheap way in finding funding to shoehorn something into a 75-year-old structure,” he said, adding that it’s very rare to receive one pot of funding for a project of this caliber.
Continue reading about Biking to the City.
Article by Nick Sucharski for the East Bay Express
Photograph by KWDesigns
© COPYRIGHT EAST BAY EXPRESS, 2010
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