Better Ways to Cross the Bay

There are only so many ways to cross San Francisco Bay—and, despite widespread frustration with the limited and often congested options, no new bridge or tunnel is on the horizon. According to the Bay Crossings Study completed by the Metropolitan Transportation Commission (MTC) in late July, a new bridge, or a tunnel for BART or other rail, could be built only by sacrificing all other transportation projects in the region for decades. The study concluded that improvements to the existing infrastructure were more cost-effective and would receive greater public support. Also, potential changes in the region's land-use planning due to a shift toward smart growth policies could significantly change regional travel patterns and reduce the need for a new crossing.

A new bridge between the Oakland-San Francisco Bay Bridge and the San Mateo Bridge has been discussed intermittently for decades. However, a 1991 study of a "southern crossing" reached the same conclusions as the most recent studycapacity-enhancing improvements were preferable to mortgaging the region's transportation future for one project. Then, as now, the pricetag was the problem. Figures for the 2002 study show that a new mid-Bay bridge, between I-238 and I-380, would mean significantly less traffic on the Hayward-San Mateo Bridge, and shorter rush hours with a small decrease in traffic on the Bay Bridge. However, it would cost $6.2$8.8 billion for a six-lane bridge, and rail would add $5$6.5 billion plus costs for stations and rail vehicles. In addition, relocation and construction impacts on existing communities and on sensitive baylands would be substantial. Less congested bridges would also lure riders off transit. Despite some strong advocates for a bridge as a visionary and complete solution, the study concluded that public support is not strong enough to overcome the financial and other obstacles, and the study committee did not forward this recommendation to MTC.

A new rail crossing by itself, using a tunnel, is even more expensive, and has considerable negative environmental impacts. Putting conventional rail under the Bay from the Peninsula to Emeryville and northward would cost $4.5 - $8 billion, and a tunnel which could serve BART would cost $7 - $11 billion. Transit use would increase, but the cost and the limited decrease in travel time make this option the least cost-effective.

In addition to the high-profile solutions presented by a bridge and/or rail crossing, the study considered a number of other alternatives, including rail service paralleling the Dumbarton bridge, and additional conventional and HOV lanes on bridges. A reversible lane on the recently widened Hayward-San Mateo Bridge would be helpful until midway through the planning period, approximately 2010, when it might be necessary to consider widening the bridge to 8 lanes.

The study also evaluated several policy issues: changes in HOV requirements, peak period congestion pricing, and the impact of smart growth land use changes. Land use changes described in the Smart Growth Strategy's "Central Cities" scenario proved to be the most effective way to decrease daily transbay vehicle trips and increase transit use, outperforming all other alternatives. Under this scenario, projected transit trips would increase by 17,000 daily, while daily transbay vehicle trips would decrease by 50,000 compared to the 2025 baseline. Although a different scenario may be chosen by the end of the Smart Growth Strategy process, it is clear that any scenario selected would have significant impacts on transbay travel.

The preferred study recommendations are divided into near-term changes which can be accomplished with existing funds, and future projects which can be done if bridge toll funding increases. (See table) In the first category are re-instatement of express bus service on the San Mateo Bridge, and a package of small engineering projects to enhance bridge access, particularly for carpools and transit. A toll increase could fund reversible lanes on the San Mateo Bridge, Dumbarton Rail, purchase of 3-door BART cars to reduce load times and speed trains through the system, express bus expansion in all three bridge corridors, and additional HOV improvements on bridges and bridge approaches.

Potential improvements which will need further study include a better approach to the Dumbarton Bridge from San Mateo and Santa Clara Counties, still more HOV lanes leading to the bridges, improved Transbay express bus and HOV treatment on the bridges, and analysis of capital improvements needed to expand BART's transbay capacity in addition to buying 3-door cars.

The dream of a new bridge may be gone. Together with the possible widening of the San Mateo Bay Bridge to 8 lanes, the "Mid-Bay Bridge" was proposed in the study report as an addition to the list of "Blueprint" projects in the next revision of the Regional Transportation Plan, as projects which are "of continuing interest to the public but do not yet have consensus and/or identified funding." However, the study committee voted against putting the new bridge on the Blueprint list, citing its anticipated impact on Peninsula traffic.

Instead, as suggested by the study, both high speed rail and expanded ferry transit will address transbay travel needs. In addition, the Smart Growth Strategy has been demonstrated to have the potential for major changes in transbay travel patterns. Other ways to cross the Bay or to travel around it will take the place of another bridge.

For more information: Larry Magid, MTC, 510-464-7819; http://www.mtc.ca.gov