San Mateo County’s bridges are among the worst in the state by some measures, but work is under way to address some of the worst of the worst — and local officials say others aren’t as bad as they might appear.
A report released last month by Transportation for America, a lobbying group campaigning for greater investment in transportation infrastructure, found that 74 of San Mateo County’s 344 bridges are considered “structurally deficient” based on federal and state data.
With 21.5 percent of its bridges considered structurally deficient, the report ranked the county sixth worst in the state and third worst in the Bay Area, behind San Francisco and Alameda counties.
What the county’s five worst-rated bridges have in common is age: the youngest among them is 62 years old and two are more than 100 years old.
“Bridges are a vital link in moving goods across the nation,” said Bob Haus, a spokesman for the California Department of Transportation, commenting on the report. “But protecting this valuable asset is becoming a challenge due to the effects of age and increasing demand.”
One of the lowest scoring bridges in the county, dating to 1924, is located along Skyline Boulevard and the Crystal Springs Dam. That bridge was closed in October, however, as part of a larger water pipeline and dam upgrade project, and completion of a new bridge is expected in summer 2013, according to the county’s Department of Public Works
Plans also are under way to repair Half Moon Bay’s Main Street Bridge at Pilarcitos Creek, built in 1900, which received a total score of four.
After Caltrans officials pointed out structural flaws, Half Moon Bay launched its own study. The city revealed the bridge was too narrow to be safe in an emergency and had wooden sidewalks that are not fully ADA-compliant and “should be replaced,” said city engineer Mo Sharma.
The city’s proposed bridge replacement is estimated to cost about $7.5 million. Last year, Half Moon Bay applied for a $6.5 million grant from the Highway Bridge Program and it is applying for more grants to make up the remaining $1 million, Sharma said.
At least one of the worst-rated bridges, in San Mateo, was deemed “deficient” in the report based on federal data, but has been rated “fair” by state officials.
According to a 2007 Caltrans report, the bridge along Railroad Avenue crossing San Mateo Creek just south of Tilton Avenue showed “no visible signs of distress in the structure,” city engineer Susanna Chan said.
A bridge is considered “structurally deficient” by Transportation for America if any of its structural components receives a rating of 4 or less out of a possible 9. State and federal officials include other factors in their assessments, such as culverts and retaining walls.
Lowest-scoring bridges in San Mateo county
Half Moon Bay: Main Street at Pilarcitos Creek, built in 1900: total: 4; deck: 0; superstructure: 4; substructure: 0
Portola State Park: Portola State Park Road at Pescadero Creek, built in 1949: total: 10; deck: 2; superstructure: 4; substructure: 4
Crystal Springs Reservoir: Skyline Boulevard at Crystal Springs Dam, built in 1924: total: 11; deck: 3; superstructure: 4; substructure: 4
San Gregorio: State Highway 1 at San Gregorio Creek, built in 1941: total: 12; deck: 2; superstructure: 5; substructure: 5
San Mateo*: Railroad Avenue at San Mateo Creek, built in 1902: total: 13; deck: 0; superstructure: 7; substructure: 6
Source: Transportation for America
* Caltrans reports from 2007 show the bridge is in “fair” condition