US Bridges

State Route 99 NB over Zeff RD & Tuolumne River

Good

Stanislaus County, California · 10-STA-099-R14.93 · Structure no. 38 0078R

Built
1963
62 years old
Condition
Good
inspected September 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
702 ft
8 main spans
Daily traffic
52,500
2015 count
Owner
State
State Highway Agency

About this bridge

State Route 99 NB over Zeff RD & Tuolumne River is a concrete continuous box beam or girders - multiple carrying State Route 99 NB over Zeff RD & Tuolumne River in Stanislaus County, California. It was built in 1963, so it is 62 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 52,500 vehicles a day, roughly 12% of them trucks, projected to reach 64,830 by 2040. The structure is 702 ft (214 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesState Route 99 NB
CrossesZeff RD & Tuolumne River
Location10-STA-099-R14.93
RouteState Highway 99
Coordinates37.62476, -120.99608
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.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating77.2 US tons
Inventory rating46.1 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20
Structure length702 ft (214 m)
Longest span96 ft (29.3 m)
Deck width46 ft (14 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic52,500 (2015)
Projected traffic64,830 by 2040
Trucks12%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 99 NB over Zeff RD & Tuolumne River built?

It was built in 1963, making it 62 years old in 2025.

What condition is State Route 99 NB over Zeff RD & Tuolumne River 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 September 2023.

How much traffic does State Route 99 NB over Zeff RD & Tuolumne River carry?

About 52,500 vehicles per day (2015 count), of which roughly 12% are trucks.

How long is State Route 99 NB over Zeff RD & Tuolumne River?

The structure is 702 ft (214 m) long with a longest span of 96 ft (29.3 m) and a deck 46 ft wide.

Who owns State Route 99 NB over Zeff RD & Tuolumne River?

It is owned by the State Highway Agency.