US Bridges

Bird Road over California Aqueduct

Poor

San Joaquin County, California · 0.5 MI N Blewett RD · Structure no. 29C0370

Built
1966
59 years old
Condition
Poor
inspected June 2024
Type
Tee Beam
Concrete Continuous
Length
154 ft
2 main spans
Daily traffic
3,491
2009 count
Owner
State
Other State Agency

About this bridge

Bird Road over California Aqueduct is a concrete continuous tee beam carrying Bird Road over California Aqueduct in San Joaquin County, California. It was built in 1966, so it is 59 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 3,491 vehicles a day, roughly 50% of them trucks, projected to reach 4,364 by 2046. The structure is 154 ft (46.9 m) long and 34 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesBird Road
CrossesCalifornia Aqueduct
Location0.5 MI N Blewett RD
RouteCounty Highway 0
Coordinates37.63008, -121.36108
Functional classRural Minor Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.8 US tons
Inventory rating23.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length154 ft (46.9 m)
Longest span75 ft (22.9 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,491 (2009)
Projected traffic4,364 by 2046
Trucks50%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerOther State Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$799,000 (2017 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Bird Road over California Aqueduct built?

It was built in 1966, making it 59 years old in 2025.

What condition is Bird Road over California Aqueduct in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2024.

How much traffic does Bird Road over California Aqueduct carry?

About 3,491 vehicles per day (2009 count), of which roughly 50% are trucks.

How long is Bird Road over California Aqueduct?

The structure is 154 ft (46.9 m) long with a longest span of 75 ft (22.9 m) and a deck 34 ft wide.

Who owns Bird Road over California Aqueduct?

It is owned by the Other State Agency and maintained by the County Highway Agency.