US Bridges

Imperial HWY-N405 over W105-N405 Connector Ramp

Good

Los Angeles County, California · 07-LA-405-R21.32-LA · Structure no. 53 2434T

Built
1989
36 years old
Condition
Good
inspected November 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
327 ft
3 main spans
Daily traffic
2,600
2019 count
Owner
State
State Highway Agency

About this bridge

Imperial HWY-N405 over W105-N405 Connector Ramp is a prestressed concrete continuous box beam or girders - multiple carrying Imperial HWY-N405 over W105-N405 Connector Ramp in Los Angeles County, California. It was built in 1989, so it is 36 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 2,600 vehicles a day, roughly 1% of them trucks, projected to reach 3,211 by 2042. The structure is 327 ft (99.7 m) long and 31 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesImperial HWY-N405
CrossesW105-N405 Connector Ramp
Location07-LA-405-R21.32-LA
RouteInterstate 405
CountyLos Angeles County
StateCalifornia
Coordinates33.93227, -118.3673
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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length327 ft (99.7 m)
Longest span132 ft (40.2 m)
Deck width31 ft (9.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,600 (2019)
Projected traffic3,211 by 2042
Trucks1%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

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 Imperial HWY-N405 over W105-N405 Connector Ramp built?

It was built in 1989, making it 36 years old in 2025.

What condition is Imperial HWY-N405 over W105-N405 Connector Ramp 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 November 2024.

How much traffic does Imperial HWY-N405 over W105-N405 Connector Ramp carry?

About 2,600 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is Imperial HWY-N405 over W105-N405 Connector Ramp?

The structure is 327 ft (99.7 m) long with a longest span of 132 ft (40.2 m) and a deck 31 ft wide.

Who owns Imperial HWY-N405 over W105-N405 Connector Ramp?

It is owned by the State Highway Agency.