US Bridges

99 Frontage RD W over Mosher Slough

Good

San Joaquin County, California · 0.8 MI S of 8 Mile Road · Structure no. 29C0066

Built
1964
61 years old
Condition
Good
inspected December 2023
Type
Slab
Concrete Continuous
Length
83 ft
3 main spans
Daily traffic
2,000
2015 count
Owner
City
City or Municipal Highway Agency

About this bridge

99 Frontage RD W over Mosher Slough is a concrete continuous slab carrying 99 Frontage RD W over Mosher Slough in San Joaquin County, California. It was built in 1964, so it is 61 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 2,000 vehicles a day, roughly 18% of them trucks, projected to reach 3,071 by 2045. The structure is 83 ft (25.3 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Carries99 Frontage RD W
CrossesMosher Slough
Location0.8 MI S of 8 Mile Road
RouteCounty Highway 0
Coordinates38.04276, -121.25898
Functional classUrban Local

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 inspectionDecember 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70.8 US tons
Inventory rating42.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length83 ft (25.3 m)
Longest span27 ft (8.2 m)
Deck width32 ft (9.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2015)
Projected traffic3,071 by 2045
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 99 Frontage RD W over Mosher Slough built?

It was built in 1964, making it 61 years old in 2025.

What condition is 99 Frontage RD W over Mosher Slough 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 December 2023.

How much traffic does 99 Frontage RD W over Mosher Slough carry?

About 2,000 vehicles per day (2015 count), of which roughly 18% are trucks.

How long is 99 Frontage RD W over Mosher Slough?

The structure is 83 ft (25.3 m) long with a longest span of 27 ft (8.2 m) and a deck 32 ft wide.

Who owns 99 Frontage RD W over Mosher Slough?

It is owned by the City or Municipal Highway Agency.