US Bridges

State Route 1 over Trancas Creek

Poor

Los Angeles County, California · 07-LA-001-56.71 · Structure no. 53 0027

Built
1927
98 years old, rebuilt 1938
Condition
Poor
inspected August 2023
Type
Tee Beam
Concrete
Length
97 ft
3 main spans
Daily traffic
17,100
2017 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Trancas Creek is a concrete tee beam carrying State Route 1 over Trancas Creek in Los Angeles County, California. It was built in 1927 and reconstructed in 1938, so it is 98 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 2 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 17,100 vehicles a day, roughly 3% of them trucks, projected to reach 24,000 by 2040. The structure is 97 ft (29.6 m) long and 84 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesTrancas Creek
Location07-LA-001-56.71
RouteState Highway 1
CountyLos Angeles County
StateCalifornia
Coordinates34.02988, -118.84172
Functional classUrban Other Principal Arterial

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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure2 CriticalAdvanced deterioration of primary structural elements. Bridge may be closed until corrective action is taken.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; extensive scour has occurred
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment9: Superior to present desirable criteria
Operating rating50.4 US tons
Inventory rating30.3 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length97 ft (29.6 m)
Longest span33 ft (10 m)
Deck width84 ft (25.6 m)
Roadway width71 ft (21.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,100 (2017)
Projected traffic24,000 by 2040
Trucks3%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 State Route 1 over Trancas Creek built?

It was built in 1927, making it 98 years old in 2025. It was reconstructed in 1938.

What condition is State Route 1 over Trancas Creek 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 August 2023.

How much traffic does State Route 1 over Trancas Creek carry?

About 17,100 vehicles per day (2017 count), of which roughly 3% are trucks.

How long is State Route 1 over Trancas Creek?

The structure is 97 ft (29.6 m) long with a longest span of 33 ft (10 m) and a deck 84 ft wide.

Who owns State Route 1 over Trancas Creek?

It is owned by the State Highway Agency.