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Bay Bridge

East Span Replacement

Planning and Design Recommendations for the East Span of the San Francisco-Oakland Bay Bridge

Adopted by the Metropolitan Transportation Commission on July 30, 1997

Finance Recommendation (1)

Recommendation 1:

The Commission should support a two year extension of tolls and establish the priority for use of the estimated $230 million as follows: first, for the additional costs for a cable-supported structure; second, for a portion of the cost of the Transbay Terminal; and third, a bicycle and pedestrian facility on the east span of the bridge should continue to be evaluated through the 30% design stage.

Design Process (2 - 3)

Recommendation 2:

Caltrans should select two design teams to develop the two cable-supported alternatives to approximately the 30% design stage so that reliable information as to seismic performance, cost, visual design, and other issues can be obtained before a final recommendation is made.

Recommendation 3:

The EDAP and Bay Bridge Design Task Force should remain in place through the 30% design stage of the project to make a final recommendation on bridge design type and thereafter to provide continuous review of final design and engineering details.

Planning Recommendations (4 - 9)

Recommendation 4:

The existing eastern span of the Bay Bridge should not be retrofitted, but replaced with a new structure.

Recommendation 5:

The new eastern span and existing western span retrofit should be designed to provide post-earthquake "lifeline" service.

Recommendation 6:

The new eastern span should have 10 traffic lanes, five in each direction, with two standard 10' shoulders in each direction as part of its base cost.

Recommendation 7:

The new eastern span does not require a dedicated bus/carpool lane. Caltrans' design should minimize weaving conflicts between high occupancy and other vehicles at the transition from the dedicated HOV approach lanes to the bridge itself.

Recommendation 8:

The new eastern span should be designed in accordance with Caltrans' proposed design loading which will accommodate the possibility of future rail service.

Recommendation 9:

The Yerba Buena Island ramps are an inherent part of the bridge and Caltrans has the responsibility to replace the ramps in order to assure safe traffic flow on the bridge.

Bridge Design Recommendations (10 - 17)

Recommendation 10:

The new eastern span should be built on the northern adjacent alignment.

Recommendation 11:

The new eastern span should have a cable-supported main span with a single vertical tower with single or multiple legs in the transverse direction and single or multiple planes of supporting cables.

Recommendation 12:

The new eastern span bridge should not be double decked. It should have two parallel separated decks on the causeway section and either parallel separated decks or a single deck on the cable-supported span.

Recommendation 13:

The structural elements of the new eastern span should be visually consistent throughout.

Recommendation 14:

The causeway section should have long, equal span lengths, although closer span lengths might be necessary just adjacent to the Oakland shore.

Recommendation 15:

For the causeway section, particular attention should be paid to the design of the supporting pier as it enters the water, including the possibility of submerging the pile cap below water.

Recommendation 16:

The cable or suspension tower on the eastern span should be no taller than the suspension towers on the existing western span.

Recommendation 17:

The "diamond" shape for the tower base should not be employed in any cable or suspension tower on the eastern span.