San Bruno B.A.R.T.

  SAN FRANCISCO--The regional Metropolitan Transportation Commission has seen the Bay Area's future, and two things seem certain: Congestion will mushroom, and it's going to cost big money to get around.

  Those likelihoods were emphasized in San Francisco last week during a public meeting on a study that took a look at how to ease the region's worsening gridlock. A second public forum will be held Wednesday in Oakland.

  The study focuses on the historic bottleneck in Bay Area transportation: The bay itself.

  Observing that transbay travel is expected to grow 40 percent through 2025, commission engineers outlined a series of measures to keep commuters moving smoothly.

  Few are easy to implement -- and some will be horrendously expensive, such as a new transbay bridge and a transbay rail tunnel for high-speed trains. Those could collectively cost up to $20 billion.

  In any event, two polls that were released at the San Francisco meeting showed that Bay Area residents favor mass transit alternatives over those that would benefit cars.

  Comments at the San Francisco meeting bore out those findings. Jim Reese, the assistant city manager for Newark, was particularly bullish on rail service along the Dumbarton Bridge corridor, one of the alternatives under consideration.

  "If realized, it will link Newark with the regional rail network," said Reese. "That will enhance smart growth. We support it completely."

  San Francisco computer consultant Eric P. Scott also liked the Dumbarton rail plan -- and said the last thing the region needs is a new bridge.

  "We shouldn't be incentivizing single-occupancy cars," Scott said. "From that perspective alone, a new bridge would be utter folly. Single drivers are the one group we shouldn't be encouraging. The most attractive alternative I see here is rail service on the Dumbarton."

  ALTERNATIVE IDEAS

  The alternatives in the MTC study -- which took almost two years to complete -- focus on fixes that could be made to the existing Bay, San Mateo- Hayward and Dumbarton bridges, as well as major new projects, such as a new transbay bridge and rail tube.

  After the Oakland meeting, the study committee will consider public comments and make their recommendations to the full commission, which is expected to adopt a final plan July 24.

  Larry Magid, the commission's project manager for the study, said staff members used several criteria to evaluate new bay crossing strategies, including cost, environmental and social impact and effectiveness in improving mobility.

  The study replaces a similar evaluation made in 1991, Magid said.

  "That only went out to 2010," he said, "and we also had to incorporate some new developments, such as the unexpectedly rapid growth we've had in the region."

  STUDY RECOMMENDATIONS

  Recommendations were made on a tripartite basis: Changes that could be undertaken with existing transit funds, ones that could be accomplished with a $1 toll increase, and transit possibilities that required further analysis.

  Transit improvements that could be made with existing funds include:

  -- Carpool lane extensions and signage additions on both sides of the Bay Bridge.

  -- Express bus service on the San Mateo Bridge.

  -- Extending FasTrak approach lanes on the San Mateo and Dumbarton toll plazas.

  Total capital costs for the projects would be about $8.5 million, with 20- year operating costs totaling $6.5 million.

  Assuming a $1 fare increase on bay bridges, the commission made the following recommendations:

  -- Additional carpool lane extensions on all three bridges.

  -- Expanded express bus service on all bridges.

  -- Reversible lanes on high-rise portions of the San Mateo Bridge.

  -- Passenger rail service on the Dumbarton Bridge corridor.

  Capital costs for these projects would total $737.5 million, and 20-year operating costs would run $606.9 million.

  Recommended for further analysis were the truly big ticket items: a new bridge that would span the bay between South San Francisco and San Leandro, a new high-speed rail crossing either under or over the bay, widening the San Mateo Bridge to eight lanes, and a major reconfiguring of the western approaches to the Dumbarton Bridge and the U.S. Highway 101 corridor.

  HIGH COSTS

  Costs? Estimates are currently somewhat unclear but astoundingly high by any measure.

  The report estimates a new bridge would require a capital investment of between $6.6 billion and $8.2 billion, with an extra $5 billion thrown in if a railway is part of the design.

  And a new rail tube that could handle both high-speed and conventional trains would cost up to $12 billion, said Brent Ogden, a project manager for Korve Engineering, a firm that participated in the study.

  Many of the proposals could be funded with either existing funds or toll increases in the $1 to $2 range, said Ogden.

  "But the rail tunnels and new bay bridge crossing could require tolls of $7 or more," Ogden said. "That's way beyond the public threshold for a toll increase."

  Ferries were not included in the recommendations, but MTC is working with the San Francisco Bay Area Water Transit Authority to evaluate several options involving expanded ferry service.

  PUBLIC SUPPORT

  Eileen Goodwin, a principal with the transportation consulting firm of Apex Strategies, said the new polls confirm that public support for increased transit service is strong in the Bay Area.

  Expansion of BART and the construction of rail lines met with the most enthusiasm, said Goodwin.

  "The projects that got the weakest support were the construction of a new bridge and the widening of existing bridges," Goodwin said.

  Goodwin said Bay area residents also champion toll increases -- to a point. The greater the increase, the more tepid the support.

  "For a $3 toll (on all bridges), the support was 77 percent," she said. "Support dropped to 61 percent for a $4 toll, 39 percent for a $5 toll and 30 percent for a $6 toll."

  Ed Regan, a San Francisco resident and Social Security pensioner who attended the San Francisco meeting, cautioned commissioners to proceed cautiously when it comes to raising tolls.

  "The problem is that there are so many people out there on low incomes," said Regan, "and there are so many places where public transit doesn't go. That means any toll increase, no matter how small, will work a hardship."

E-mail the writer at glenmartin@sfchronicle.com.