While the city doesn't expect them to collapse in such a quake, it's believed they may suffer some damage.
Even so, city engineers say the overall C-minus grade isn't as bad as it sounds and that ultimately every bridge in Los Angeles is safe for driving.
"In general, we are in good shape," Shailesh "Sunny" Patel, with the bureau's Structural Engineering Division, told the Board of Public Works.
Patel said bridges were rated based on federal guidelines on structural integrity, load rating capacity, serviceability, ability to provide an evacuation route during an emergency, and a multitude of other factors.
City News Service contributed to this report.