US Bridges

State Route 99 NB over Atwater Blvd & UP RR

Good

Merced County, California · 10-MER-099-23.46-ATW · Structure no. 39 0128R

Built
1957
68 years old, rebuilt 1988
Condition
Good
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
460 ft
6 main spans
Daily traffic
25,000
2015 count
Owner
State
State Highway Agency

About this bridge

State Route 99 NB over Atwater Blvd & UP RR is a steel stringer/multi-beam or girder carrying State Route 99 NB over Atwater Blvd & UP RR in Merced County, California. It was built in 1957 and reconstructed in 1988, so it is 68 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 25,000 vehicles a day, roughly 25% of them trucks, projected to reach 30,413 by 2046. The structure is 460 ft (140.2 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesState Route 99 NB
CrossesAtwater Blvd & UP RR
Location10-MER-099-23.46-ATW
RouteState Highway 99
Coordinates37.35036, -120.6231
Functional classUrban Principal Arterial - Other Freeway or Expressway

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 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72.1 US tons
Inventory rating43.2 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length460 ft (140.2 m)
Longest span90 ft (27.4 m)
Deck width42 ft (12.7 m)
Roadway width38 ft (11.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,000 (2015)
Projected traffic30,413 by 2046
Trucks25%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate 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 State Route 99 NB over Atwater Blvd & UP RR built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 1988.

What condition is State Route 99 NB over Atwater Blvd & UP RR 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 2024.

How much traffic does State Route 99 NB over Atwater Blvd & UP RR carry?

About 25,000 vehicles per day (2015 count), of which roughly 25% are trucks.

How long is State Route 99 NB over Atwater Blvd & UP RR?

The structure is 460 ft (140.2 m) long with a longest span of 90 ft (27.4 m) and a deck 42 ft wide.

Who owns State Route 99 NB over Atwater Blvd & UP RR?

It is owned by the State Highway Agency.