US Bridges

Twisselman Road over California Aqueduct

Poor

Kern County, California · 2.7 MI East Holloway Road · Structure no. 50C0205

Built
1965
60 years old
Condition
Poor
inspected March 2023
Type
Tee Beam
Concrete Continuous
Length
226 ft
3 main spans
Daily traffic
800
2011 count
Owner
State
Other State Agency

About this bridge

Twisselman Road over California Aqueduct is a concrete continuous tee beam carrying Twisselman Road over California Aqueduct in Kern County, California. It was built in 1965, so it is 60 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 800 vehicles a day, roughly 10% of them trucks, projected to reach 1,038 by 2041. The structure is 226 ft (68.9 m) long and 32 ft wide. If it were closed, the detour would be 5.6 mi (9 km).

CarriesTwisselman Road
CrossesCalifornia Aqueduct
Location2.7 MI East Holloway Road
RouteCounty Highway 0
Coordinates35.73132, -119.80384
Functional classRural Major 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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 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 rating50.7 US tons
Inventory rating39.2 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length226 ft (68.9 m)
Longest span86 ft (26.2 m)
Deck width32 ft (9.9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic800 (2011)
Projected traffic1,038 by 2041
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5.6 mi (9 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$1.1 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Twisselman Road over California Aqueduct built?

It was built in 1965, making it 60 years old in 2025.

What condition is Twisselman 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 March 2023.

How much traffic does Twisselman Road over California Aqueduct carry?

About 800 vehicles per day (2011 count), of which roughly 10% are trucks.

How long is Twisselman Road over California Aqueduct?

The structure is 226 ft (68.9 m) long with a longest span of 86 ft (26.2 m) and a deck 32 ft wide.

Who owns Twisselman Road over California Aqueduct?

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