US Bridges

Treasure Island RD over Sidehill

Fair

San Francisco County, California · Jso Shv #4/ Jno Shv #7B · Structure no. 34C0085

Built
1938
87 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete Continuous
Length
132 ft
10 main spans
Daily traffic
3,000
2020 count
Owner
County
County Highway Agency

About this bridge

Treasure Island RD over Sidehill is a concrete continuous slab carrying Treasure Island RD over Sidehill in San Francisco County, California. It was built in 1938, so it is 87 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 3,000 vehicles a day, roughly 3% of them trucks, projected to reach 6,000 by 2040. The structure is 132 ft (40.2 m) long and 19 ft wide. If it were closed, the detour would be 2.5 mi (4 km).

CarriesTreasure Island RD
CrossesSidehill
LocationJso Shv #4/ Jno Shv #7B
RouteCity Street 0
Coordinates37.80964, -122.37069
Functional classUrban Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.3 US tons
Inventory rating18.2 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans10
Design loadUnknown
Structure length132 ft (40.2 m)
Longest span13 ft (3.9 m)
Deck width19 ft (5.8 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2020)
Projected traffic6,000 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed2.5 mi (4 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Treasure Island RD over Sidehill built?

It was built in 1938, making it 87 years old in 2025.

What condition is Treasure Island RD over Sidehill 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 April 2023.

How much traffic does Treasure Island RD over Sidehill carry?

About 3,000 vehicles per day (2020 count), of which roughly 3% are trucks.

How long is Treasure Island RD over Sidehill?

The structure is 132 ft (40.2 m) long with a longest span of 13 ft (3.9 m) and a deck 19 ft wide.

Who owns Treasure Island RD over Sidehill?

It is owned by the County Highway Agency.