Infrastructure
Updated: july 2025

Bridge Condition

Definition: Bridge condition here is measured by the share of bridge and overpass deck area rated as “good,” “fair” and “poor” according to the Federal Highway Administration’s (FHWA) National Bridge Inventory (NBI).
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29%

of Bay Area bridge deck area was rated "good" in 2025

60%

of Bay Area bridge deck area was rated "fair” in 2025

11%

of Bay Area bridge deck area was rated "poor” in 2025

Introduction

How well are the Bay Area’s bridges maintained?

Bridges define the Bay Area. From the Golden Gate Bridge to the Bay Bridge, they remain iconic symbols of the region, recognizable to people across the world. But they face great threats from natural hazards, as witnessed in 1989 when the Loma Prieta earthquake seriously damaged the Bay Bridge. It is critical to ensure that the region’s bridges are in good condition so not a single life is lost when the next quake hits.

Regional Performance

The condition of Bay Area bridges has varied over the past decades.

Bay Area bridges and overpasses were generally in good condition at the start of the 1990s, the earliest that this data is available. Bridge condition worsened in the late 1990s and early 2000s. The percentage of bridge deck area rated as “poor” hit a peak in 2003 at approximately 34%. In the early 2010s, seismic retrofit programs on highway bridges, as well as upgrades to elevated freeway structures helped the region reverse that trajectory. However, during the late 2010s and into the 2020s, bridge condition declined, with 60% of bridge deck area rated as “fair” in 2025.

2016

had the lowest percentage of Bay Area bridge deck area rated “poor” since 1992, at 7%

1996

had the highest percentage of Bay Area bridge deck area rated “good” since 1992, at 61%

Historical Trend for Bridge Condition

Stacked area chart depicting the historical trend in bridge condition
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Local Focus

Most Bay Area counties have seen improved bridge and overpass conditions over the past two decades.

Over the past two decades, many counties in the Bay Area have seen a decrease in their respective share of bridge deck area being rated as “poor.” For example, from 2005 to 2025, the counties of Alameda, Contra Costa, Marin, San Francisco, Santa Clara, Solano and Sonoma all saw drops in the range of 16 to 40 percentage points. Notably, San Francisco saw a dramatic drop from 41% in 2012 to just 0.1% in 2022, following extensive structural repairs during the 2010s.

However, in more recent years, some counties have experienced a slight uptick in their respective share of bridge deck area rated as “poor.” For example, in San Mateo County, the “poor” bridge deck area percentage increased from 7% to 37% between 2016 and 2025. Additionally, the counties of Alameda, Contra Costa, Napa and Solano all saw increases in the range of one to 10 percentage points during this time period.

39%

of bridge and overpass deck area in Solano County were rated as "good” in 2025, the highest in the Bay Area

37%

of bridge and overpass deck area in San Mateo County were rated as "poor” in 2025, the highest in the Bay Area

Bridge Condition Ratings Map (2025)

Bridge Conditions
Poor
Fair
Good
Approximate Daily Traffic Volumes
1K
550K
Click on a shape on the map for more information.

Sources & Methodology

Methodology Notes

Bridge deck area rating definitions (Good, Fair, Poor) are from the FHWA NBI. Bridge condition for the region and counties was calculated by summing all of the bridge deck area by rating and dividing it by total bridge deck area. In 2018, the FHWA updated its bridge condition metrics, deprecating the terms “Structurally Deficient” and “Structurally Sound” in favor of as "Good", "Fair" and "Poor," which are used in this Vital Signs indicator for current and historical data. Data for the years 1997 and 2004 are omitted due to data anomalies in those years.

Data Sources

The Vital Signs initiative is led by the Metropolitan Transportation Commission (MTC) and the Association of Bay Area Governments (ABAG).

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association of bay area governments logo
bay area air quality management district logo
san francisco bay conservation and development commission logo
bay area regional collaborative logo

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