US Bridges

Tassajara Road over Tassajara Creek

Fair

Contra Costa County, California · 1.8 MI N County Line · Structure no. 28C0157

Built
1995
30 years old
Condition
Fair
inspected November 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
84 ft
1 main span
Daily traffic
7,539
2013 count
Owner
County
County Highway Agency

About this bridge

Tassajara Road over Tassajara Creek is a prestressed concrete box beam or girders - multiple carrying Tassajara Road over Tassajara Creek in Contra Costa County, California. It was built in 1995, so it is 30 years old, younger 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 6 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 7,539 vehicles a day, roughly 3% of them trucks, projected to reach 6,412 by 2046. The structure is 84 ft (25.6 m) long and 38 ft wide. If it were closed, the detour would be 15.5 mi (25 km).

Location

Open in Google Maps
CarriesTassajara Road
CrossesTassajara Creek
Location1.8 MI N County Line
RouteCounty Highway 0
CountyContra Costa County
StateCalifornia
Coordinates37.76438, -121.86658
Functional classRural Principal Arterial - Other

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length84 ft (25.6 m)
Longest span80 ft (24.4 m)
Deck width38 ft (11.7 m)
Roadway width35 ft (10.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,539 (2013)
Projected traffic6,412 by 2046
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed15.5 mi (25 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Tassajara Road over Tassajara Creek built?

It was built in 1995, making it 30 years old in 2025.

What condition is Tassajara Road over Tassajara Creek 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 November 2024.

How much traffic does Tassajara Road over Tassajara Creek carry?

About 7,539 vehicles per day (2013 count), of which roughly 3% are trucks.

How long is Tassajara Road over Tassajara Creek?

The structure is 84 ft (25.6 m) long with a longest span of 80 ft (24.4 m) and a deck 38 ft wide.

Who owns Tassajara Road over Tassajara Creek?

It is owned by the County Highway Agency.