US Bridges

State Route 60 over Diamond Bar

Fair

Los Angeles County, California · 07-LA-060-R25.56-DMBR · Structure no. 53 1899

Built
1970
55 years old
Condition
Fair
inspected February 2025
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
156 ft
1 main span
Daily traffic
223,000
2015 count
Owner
State
State Highway Agency

About this bridge

State Route 60 over Diamond Bar is a prestressed concrete box beam or girders - multiple carrying State Route 60 over Diamond Bar in Los Angeles County, California. It was built in 1970, so it is 55 years old, older 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 5 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 223,000 vehicles a day, roughly 11% of them trucks, projected to reach 347,368 by 2047. The structure is 156 ft (47.5 m) long and 148 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesState Route 60
CrossesDiamond Bar
Location07-LA-060-R25.56-DMBR
RouteState Highway 60
CountyLos Angeles County
StateCalifornia
Coordinates34.023, -117.81177
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70.8 US tons
Inventory rating42.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length156 ft (47.5 m)
Longest span155 ft (47.2 m)
Deck width148 ft (45.1 m)
Roadway width144 ft (43.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic223,000 (2015)
Projected traffic347,368 by 2047
Trucks11%
Lanes on structure11
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed5 mi (8 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 60 over Diamond Bar built?

It was built in 1970, making it 55 years old in 2025.

What condition is State Route 60 over Diamond Bar 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 February 2025.

How much traffic does State Route 60 over Diamond Bar carry?

About 223,000 vehicles per day (2015 count), of which roughly 11% are trucks.

How long is State Route 60 over Diamond Bar?

The structure is 156 ft (47.5 m) long with a longest span of 155 ft (47.2 m) and a deck 148 ft wide.

Who owns State Route 60 over Diamond Bar?

It is owned by the State Highway Agency.