US Bridges

State Route 115 over Alamo River

Good

Imperial County, California · 11-IMP-115-L10.31-HOLT · Structure no. 58 0007

Built
1955
70 years old, rebuilt 1990
Condition
Good
inspected October 2024
Type
Tee Beam
Concrete Continuous
Length
252 ft
6 main spans
Daily traffic
5,400
2018 count
Owner
State
State Highway Agency

About this bridge

State Route 115 over Alamo River is a concrete continuous tee beam carrying State Route 115 over Alamo River in Imperial County, California. It was built in 1955 and reconstructed in 1990, so it is 70 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 5,400 vehicles a day, roughly 40% of them trucks, projected to reach 8,906 by 2041. The structure is 252 ft (76.8 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesState Route 115
CrossesAlamo River
Location11-IMP-115-L10.31-HOLT
RouteState Highway 115
Coordinates32.80772, -115.38814
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length252 ft (76.8 m)
Longest span45 ft (13.7 m)
Deck width46 ft (14 m)
Roadway width43 ft (13 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,400 (2018)
Projected traffic8,906 by 2041
Trucks40%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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 115 over Alamo River built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 1990.

What condition is State Route 115 over Alamo River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2024.

How much traffic does State Route 115 over Alamo River carry?

About 5,400 vehicles per day (2018 count), of which roughly 40% are trucks.

How long is State Route 115 over Alamo River?

The structure is 252 ft (76.8 m) long with a longest span of 45 ft (13.7 m) and a deck 46 ft wide.

Who owns State Route 115 over Alamo River?

It is owned by the State Highway Agency.