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California bridge conditions

25,975 inventoried bridges · 1,284 rated poor · county by county

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled

The worst bridge in California?

By the measure that matters most - the most traffic on a poor rating - it is Interstate 110 over Slauson Ave & BNSF Ry in Los Angeles County, built 1996, carrying about 300,000 vehicles a day. That is a repair-priority flag, not a collapse warning: what a poor rating does and does not mean. See the worst bridge in every state.

Good 47.1% · Fair 47.9% · Poor 4.9% of 25,975 bridges

Bridge conditions by county

Sorted by the number of poor-rated bridges. Click any county for its full bridge list.

CountyBridgesRated poorPoor %
Los Angeles County3,549942.6%
San Joaquin County655639.6%
San Bernardino County1,422624.4%
Contra Costa County622569.0%
Stanislaus County3865213.5%
Santa Clara County966434.5%
Alameda County662426.3%
San Diego County1,632392.4%
San Mateo County3613710.2%
Kern County668375.5%
Fresno County921353.8%
Imperial County445357.9%
Orange County1,181332.8%
Sonoma County611325.2%
Santa Cruz County1943216.5%
Mendocino County356277.6%
Monterey County378277.1%
Siskiyou County425255.9%
Butte County440245.5%
Solano County374246.4%
Madera County250249.6%
Merced County532234.3%
San Luis Obispo County402225.5%
Humboldt County399215.3%
Tehama County447214.7%
San Francisco County1442013.9%
Nevada County1371913.9%
Tulare County607183.0%
Riverside County1,120181.6%
Glenn County240177.1%
Placer County349164.6%
Sutter County1211613.2%
Sacramento County737162.2%
Marin County207167.7%
Santa Barbara County421163.8%
Amador County611524.6%
Ventura County501122.4%
Lake County131129.2%
Colusa County213125.6%
Yolo County274124.4%
Mariposa County1091211.0%
Shasta County493112.2%
El Dorado County192115.7%
Del Norte County9799.3%
Yuba County12797.1%
Lassen County10887.4%
Napa County16085.0%
Tuolumne County12586.4%
Trinity County19473.6%
San Benito County7679.2%
Kings County16963.6%
Calaveras County10865.6%
Plumas County16553.0%
Sierra County6646.1%
Mono County5635.4%
Alpine County3326.1%
Inyo County6922.9%
Modoc County8711.1%

The 25 busiest poor-rated bridges in California

BridgeCountyBuiltVehicles/dayCondition
Interstate 110 over Slauson Ave & BNSF RyLos Angeles County, CA1996300,000Poor
U.S. Highway 101 over Kester AveLos Angeles County, CA1959293,000Poor
Interstate 405 over Vermont Ave 190TH StLos Angeles County, CA1962269,000Poor
Interstate 805 over Telegraph Canyon DrainSan Diego County, CA1971250,000Poor
State Route 134 over Pacific AveLos Angeles County, CA1967240,000Poor
Interstate 680 over Monument BoulevardContra Costa County, CA1998235,000Poor
U.S. Highway 101 over Cesar Chavez BlvdSan Francisco County, CA1951234,000Poor
State Route 55 over Lincoln AveOrange County, CA1961227,000Poor
Interstate 880 over Crandall CreekAlameda County, CA1958225,000Poor
Rte 110 over Torrance BlvdLos Angeles County, CA1962218,000Poor
Route 105 & Lrt over Wright RoadLos Angeles County, CA1993217,000Poor
Interstate 80 over Suisun CreekSolano County, CA1932202,000Poor
Interstate 5 over Rte 163 ConnectorsSan Diego County, CA1961199,000Poor
Interstate 880 over Patterson SloughAlameda County, CA1957198,000Poor
U.S. Highway 101 over Cordilleras CreekSan Mateo County, CA1930195,000Poor
Interstate 680 over Laurel DriveContra Costa County, CA1964192,200Poor
Interstate 80 over Green Valley CreekSolano County, CA1928189,000Poor
Interstate 80 over El Portal DriveContra Costa County, CA1956179,000Poor
Interstate 80 over State Route 4 & RampsContra Costa County, CA1958179,000Poor
Interstate 280 over Southgate AvenueSan Mateo County, CA1967178,000Poor
U.S. Highway 101 over Argyle Av & Franklin AvLos Angeles County, CA1953175,000Poor
NB and SB Rte 280 over Lyell StreetSan Francisco County, CA1964170,000Poor
I 280 N Al Line over 280/101 InterchangeSan Francisco County, CA1960170,000Poor
Interstate 680 over Grayson CreekContra Costa County, CA1962169,000Poor
SR 55 over S405-n55 ConnectorOrange County, CA1966167,000Poor

Frequently asked questions

How many bridges in California are in poor condition?

1,284 of California's 25,975 inventoried highway bridges are rated in poor condition (4.9%) in the 2025 National Bridge Inventory. 'Poor' is FHWA's classification for a bridge whose deck, superstructure, or substructure is rated 4 or lower on the 0-9 scale; it was formerly called 'structurally deficient'.

Are the poor-rated bridges in California safe to drive on?

A poor rating flags advanced deterioration that needs repair or close monitoring; it does not by itself mean a bridge is unsafe. Bridges judged unsafe are closed or restricted to lighter loads by the owner. Inspections continue on all open bridges, generally at least every 24 months under the National Bridge Inspection Standards.

Source: FHWA National Bridge Inventory, 2025 vintage, reported by the California DOT.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.