For Immediate Release
MTC NARROWS CHOICES FOR NEW BAY BRIDGE SPAN
The Engineering and Design Advisory Panel, technical advisors to MTC's Bay Bridge Design Task Force, last week selected four designs for further development from an array presented by T.Y. Lin International/Moffatt & Nichol Engineers, the architectural and engineering design team for the new bridge under contract to Caltrans.
"We now want to hear from Bay Area residents about what they think of these designs," said Mary King, chair of the Bay Bridge Design Task Force. "Since they are progressing beyond basic concepts, the public can get a much clearer idea of what the actual choices are. MTC is offering several ways for everyone to view these designs and to submit their opinions. We hope to hear from as many people as possible to help guide us in making a final decision in June."
The four semifinal design choices for the new eastern span consist of two basic types of bridges -- self-anchored suspension and cable-stayed -- each offered with the option of a single tower or twin towers. In the single-tower designs, the tower stands in the middle of the side-by-side road decks. In the twin-tower designs, each deck is supported by two-legged towers that create 530-foot high portals through which the roadways pass.
Different treatments of the supporting cables are being considered. Under one design option, for example, the cables are spread to the outside of the deck on the west (Yerba Buena Island) side of the tower and anchored in between the decks on the Oakland side.
Visually, the primary difference between the suspension and cable-stayed designs is in the slope of the main cables -- curved or "relaxed" for the suspension and straight or "rigid" for the cable-stayed. There also are important engineering differences in how the weight of the road decks is transferred by the cables to the towers, how the two types of bridges are constructed and cost.
All four of the proposed designs include options for bicycle/pedestrian lanes that are separated from vehicular traffic.
MTC's Bay Bridge Design Task Force and its Engineering and Design Advisory Panel (EDAP) have scheduled aseries of meetings in the next three months to review refinements of the four designs and to determine a final choice that will be recommended to the full Commission on June 24. The next Task Force meeting will be on Wednesday, April 8, and the next EDAP meeting on Wednesday, April 15. Both meetings will begin at 1 p.m. in the MTC Auditorium at the MetroCenter, 101 8th Street in Oakland.
The public may view renderings of the four proposed bridge designs at the MTC offices and on the MTC web-site: <www.mtc.ca.gov>.
Opinions on the designs should be submitted in one of the following forms:
Metropolitan Transportation Commission • 101 Eighth Street, Oakland, California 94607
This page was last modified Friday February 27, 2009
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