State Route 57 over Diamond Bar Blvd
FairLos Angeles County, California · 07-LA-057-R1.94-DMBR · Structure no. 53 2162
- Built
- 1972
- 53 years old, rebuilt 1998
- Condition
- Fair
- inspected August 2024
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete
- Length
- 156 ft
- 1 main span
- Daily traffic
- 198,000
- 2017 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 57 over Diamond Bar Blvd is a prestressed concrete box beam or girders - multiple carrying State Route 57 over Diamond Bar Blvd in Los Angeles County, California. It was built in 1972 and reconstructed in 1998, so it is 53 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 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 198,000 vehicles a day, roughly 8% of them trucks, projected to reach 233,532 by 2042. The structure is 156 ft (47.5 m) long and 161 ft wide.
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 57 over Diamond Bar Blvd built?
It was built in 1972, making it 53 years old in 2025. It was reconstructed in 1998.
What condition is State Route 57 over Diamond Bar Blvd 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 August 2024.
How much traffic does State Route 57 over Diamond Bar Blvd carry?
About 198,000 vehicles per day (2017 count), of which roughly 8% are trucks.
How long is State Route 57 over Diamond Bar Blvd?
The structure is 156 ft (47.5 m) long with a longest span of 154 ft (46.9 m) and a deck 161 ft wide.
Who owns State Route 57 over Diamond Bar Blvd?
It is owned by the State Highway Agency.