US Bridges

Alum Rock Ave over Interstate 680

Fair

Santa Clara County, California · 04-SCL-680-M1.74-SJS · Structure no. 37 0290

Built
1974
51 years old
Condition
Fair
inspected April 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
299 ft
2 main spans
Daily traffic
28,500
2009 count
Owner
State
State Highway Agency

About this bridge

Alum Rock Ave over Interstate 680 is a prestressed concrete continuous box beam or girders - multiple carrying Alum Rock Ave over Interstate 680 in Santa Clara 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 fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 28,500 vehicles a day, roughly 2% of them trucks, projected to reach 44,856 by 2042. The structure is 299 ft (91.1 m) long and 102 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesAlum Rock Ave
CrossesInterstate 680
Location04-SCL-680-M1.74-SJS
RouteCity Street 0
CountySanta Clara County
StateCalifornia
Coordinates37.35932, -121.84149
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.1 US tons
Inventory rating48.6 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length299 ft (91.1 m)
Longest span164 ft (50 m)
Deck width102 ft (31.1 m)
Roadway width76 ft (23.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,500 (2009)
Projected traffic44,856 by 2042
Trucks2%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed0.6 mi (1 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 Alum Rock Ave over Interstate 680 built?

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

What condition is Alum Rock Ave over Interstate 680 in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2024.

How much traffic does Alum Rock Ave over Interstate 680 carry?

About 28,500 vehicles per day (2009 count), of which roughly 2% are trucks.

How long is Alum Rock Ave over Interstate 680?

The structure is 299 ft (91.1 m) long with a longest span of 164 ft (50 m) and a deck 102 ft wide.

Who owns Alum Rock Ave over Interstate 680?

It is owned by the State Highway Agency.