Peninsula drivers be forewarned: The Dumbarton Bridge will shut down for two full weekends and could lose a lane or two for at least 100 nights during seismic work that is expected to last 2½ years on the span.
Work to reinforce the 1.6-mile-long bridge for the next big earthquake could begin as soon as Oct. 1, and drivers will soon receive a deluge of information from transportation officials on which three-day weekends the span will shut down entirely to traffic, and also the days and hours some lanes will be closed, Caltrans project manager Mo Pazooki said.
On Wednesday, the Bay Area Toll Authority approved the $75 million needed for seismic upgrades to the bridge, which spans from Menlo Park to Fremont. Groundbreaking would follow 55 days after the contractor is awarded the contract, Pazooki said.
During the project’s 2½-year duration, Caltrans estimates there will be lane closures on or leading up to the bridge on more than 100 nights, but that could change as the contractor maps out its work schedule on the span. The bridge offers three traffic lanes in each direction.
“They might decide they need 50 nights,” Pazooki said.
The lane closures would be at night — likely one-lane closures beginning at 9 p.m. and two-lane closures starting around 11 p.m. and lasting until around 4 or 5 a.m., he said.
While dates for the two full weekend closures haven’t been determined, drivers will have plenty of warning before the bridge shuts down. The closures will likely occur during three-day holiday weekends.
At least 21 days prior to the bridge closure, Caltrans will erect around 190 portable warning signs along roadways in San Mateo and Santa Clara counties, Pazooki said. Months before the bridge is closed, the permanent signs on freeway overpasses will signal warnings, he said.
There will also be plenty more closure notices in the media, much like was done prior to Bay Bridge closures.
“There is going to be a tremendous amount of public outreach,” Pazooki said.
The funds to seismically retrofit the Dumbarton Bridge are being paid for by toll increases. The last increase came July 1, when tolls for six of the Bay Area’s seven state-owned bridges increased from $4 to $5.
The Dumbarton Bridge could be closed for as many as 100 days to undergo seismic work.
1.6 Miles of bridge
2 Weekend bridge closures predicted for upgrades
2½ years Duration for seismic upgrades
3 Lanes in each direction
$9.4 million Tolls collected in FY2008-09 on bridge
$75 million Funding for bridge upgrades approved by the Bay Area Toll Authority on Wednesday
190 Portable warning signs to inform drivers about bridge closures
81,000 Cars that cross the bridge daily