A Bay Bridge for Everyone By Gernot Huber

Imagine a day six to eight years from now when San Franciscans will argue about whether the Golden Gate or the Bay Bridge is a better scenic walk. Imagine combining a visit to your friends across the bay with a pleasant and safe bike ride complete with incredible vistas. Imagine reducing the load on our gridlocked transportation infrastructure and getting some great exercise bike-commuting between the East Bay and San Francisco.

Alternative B, doesn't require deck replacement, $160 million.
Caltrans has completed a feasibility study for a multi-use path on the west span of the Bay Bridge, and it certainly looks promising. The path will serve cyclists and pedestrians while also being used for bridge maintenance. The wheelchair-accessible multi-use path will be a keystone element in the Bay Area's network of transportation alternatives. It will also be a civic structure to be proud of, a first-rate tourist attraction, and on top of it all, will provide relief from traffic lane closures for those who drive across the Bay Bridge.

Alternative A, comparatively heavy, $387 million
As proposed, the path will run on both sides of the upper deck of the west span from San Francisco to Yerba Buena Island, and will connect directly to the multi-use path on the new east span of the Bay Bridge. The paths will be twice as wide as the paths on the Golden Gate Bridge, ensuring plenty of room for pedestrians and bicyclists as well as maintenance crews. At least one path will always be accessible to bicyclists.

Caltrans has created two versions of the plan which are functionally identical but differ aesthetically, though both comply with historic preservation laws. Alternative A blends into the existing structure by using the design language of the historical bridge, but is comparatively heavy. This version's estimated price tag is $387 million, because the weight of the path needs to be offset by a replacement of one road deck of the bridge with lighter materials. Alternative B is a lightweight version that only minimally obscures the bridge, does not require the deck replacement, and will thus only cost around $160 million. (As a comparison, the price tag for the recent one-mile-long Nimitz Freeway replacement was $800 million.)

So which version is better? I'd say whichever one can secure the necessary funding. Something to keep in mind, though, is that the auto decks of the bridge will probably have to be replaced at some point during the remaining 75-year life span of the bridge, though Caltrans does not have an official estimate of when that will have to occur. But if it is true, then the higher cost of Alternative A would be offset by the savings of not having to replace the deck in the future, thus making the two alternatives equal in real cost.

Caltrans seems to be fully supportive of the plan, and has confirmed that using the path for maintenance access will reduce maintenance costs and increase safety for Caltrans workers and motor vehicle occupants, while creating less hassle for car drivers by greatly reducing the frequency of car lane closures. This aspect of the proposal may become a major selling point, as it provides a real benefit even for those Bay Area residents who don't yet use their bicycles for everyday transportation. It will also reduce the real cost of the path significantly, depending on the bridge maintenance cost savings over the next 75 years.

To gauge the potential of such a path, let's compare it with the Golden Gate Bridge path. Between 500 and 3,500 cyclists use the Golden Gate path on weekdays, many of them commuters. The Bay Bridge is a much larger potential commute corridor than the Golden Gate Bridge, with 20 times more bike commuters living near the east end of the Bay Bridge than near the north end of the Golden Gate. Moreover, the commute to downtown San Francisco from the East Bay is shorter and flatter than the commute from Marin. It's estimated that the number of cyclists crossing the Bay Bridge on any given weekday could reach 10,000, while even the most conservative estimates run about 2,000. Such volumes of bike commuters will spell significant rush hour relief for car commuters and BART riders alike.

This proposal is worth the investment. It is a multi-functional enhancement of the Bay Bridge with benefits for recreation, bridge maintenance, car drivers, tourists and tourist-dependent businesses, as well as bicyclists. As such, the multi-use path proposal delivers maximum value for the money spent and represents a substantial improvement to the Bay Area's transportation system.