US Bridges

State Route 91 over Susana RD

Good

Los Angeles County, California · 07-LA-091-R10.81-COM · Structure no. 53 2252

Built
1974
51 years old
Condition
Good
inspected June 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
168 ft
1 main span
Daily traffic
222,000
2017 count
Owner
State
State Highway Agency

About this bridge

State Route 91 over Susana RD is a prestressed concrete box beam or girders - multiple carrying State Route 91 over Susana RD in Los Angeles County, California. It was built in 1974, so it is 51 years old, younger 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 222,000 vehicles a day, roughly 6% of them trucks, projected to reach 243,405 by 2040. The structure is 168 ft (51.2 m) long and 196 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesState Route 91
CrossesSusana RD
Location07-LA-091-R10.81-COM
RouteState Highway 91
Coordinates33.87323, -118.2074
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.4 US tons
Inventory rating50.7 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length168 ft (51.2 m)
Longest span168 ft (51.2 m)
Deck width196 ft (59.7 m)
Roadway width191 ft (58.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic222,000 (2017)
Projected traffic243,405 by 2040
Trucks6%
Lanes on structure14
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 91 over Susana RD built?

It was built in 1974, making it 51 years old in 2025.

What condition is State Route 91 over Susana RD 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 June 2023.

How much traffic does State Route 91 over Susana RD carry?

About 222,000 vehicles per day (2017 count), of which roughly 6% are trucks.

How long is State Route 91 over Susana RD?

The structure is 168 ft (51.2 m) long with a longest span of 168 ft (51.2 m) and a deck 196 ft wide.

Who owns State Route 91 over Susana RD?

It is owned by the State Highway Agency.