US Bridges

Interstate 405 over Montana Ave

Good

Los Angeles County, California · 07-LA-405-32.50-LA · Structure no. 53 0712

Built
1956
69 years old, rebuilt 2014
Condition
Good
inspected May 2023
Type
Box Beam or Girders - Multiple
Concrete
Length
66 ft
1 main span
Daily traffic
283,000
2019 count
Owner
State
State Highway Agency

About this bridge

Interstate 405 over Montana Ave is a concrete box beam or girders - multiple carrying Interstate 405 over Montana Ave in Los Angeles County, California. It was built in 1956 and reconstructed in 2014, so it is 69 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 283,000 vehicles a day, roughly 10% of them trucks, projected to reach 375,110 by 2040. The structure is 66 ft (20.1 m) long and 164 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesInterstate 405
CrossesMontana Ave
Location07-LA-405-32.50-LA
RouteInterstate 405
Coordinates34.06714, -118.46134
Functional classUrban Principal Arterial - Interstate

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 inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment9: Superior to present desirable criteria
Operating rating32.5 US tons
Inventory rating22.5 US tons

Structure

MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length66 ft (20.1 m)
Longest span61 ft (18.6 m)
Deck width164 ft (50.1 m)
Roadway width159 ft (48.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic283,000 (2019)
Projected traffic375,110 by 2040
Trucks10%
Lanes on structure10
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 Interstate 405 over Montana Ave built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 2014.

What condition is Interstate 405 over Montana Ave 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 May 2023.

How much traffic does Interstate 405 over Montana Ave carry?

About 283,000 vehicles per day (2019 count), of which roughly 10% are trucks.

How long is Interstate 405 over Montana Ave?

The structure is 66 ft (20.1 m) long with a longest span of 61 ft (18.6 m) and a deck 164 ft wide.

Who owns Interstate 405 over Montana Ave?

It is owned by the State Highway Agency.