US Bridges

White Road over Cunninham Slough

Fair

Contra Costa County, California · 40 W of Pier 3 Pk Area · Structure no. DAPAMCCON000448

Built
1945
80 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
129 ft
11 main spans
Daily traffic
11
2019 count
Owner
Federal
Army

About this bridge

White Road over Cunninham Slough is a wood or timber stringer/multi-beam or girder carrying White Road over Cunninham Slough in Contra Costa County, California. It was built in 1945, so it is 80 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 11 vehicles a day, projected to reach 44 by 2044. The structure is 129 ft (39.2 m) long and 24 ft wide.

Location

Open in Google Maps
CarriesWhite Road
CrossesCunninham Slough
Location40 W of Pier 3 Pk Area
CountyContra Costa County
StateCalifornia
Coordinates38.05635, -122.016
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans11
Design loadHS 20
Structure length129 ft (39.2 m)
Longest span12 ft (3.6 m)
Deck width24 ft (7.4 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11 (2019)
Projected traffic44 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerArmy
Maintained byArmy
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$90,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was White Road over Cunninham Slough built?

It was built in 1945, making it 80 years old in 2025.

What condition is White Road over Cunninham Slough in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2023.

How much traffic does White Road over Cunninham Slough carry?

About 11 vehicles per day (2019 count).

How long is White Road over Cunninham Slough?

The structure is 129 ft (39.2 m) long with a longest span of 12 ft (3.6 m) and a deck 24 ft wide.

Who owns White Road over Cunninham Slough?

It is owned by the Army.