US Bridges

Treasure Island RD over Sidehill

Fair

San Francisco County, California · Jno Treas Island Shv #8 · Structure no. 34C0080

Built
1938
87 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
180 ft
7 main spans
Daily traffic
3,000
2020 count
Owner
County
County Highway Agency

About this bridge

Treasure Island RD over Sidehill is a steel stringer/multi-beam or girder 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 9,000 by 2040. The structure is 180 ft (54.9 m) long and 37 ft wide. If it were closed, the detour would be 2.5 mi (4 km).

Location

Open in Google Maps
CarriesTreasure Island RD
CrossesSidehill
LocationJno Treas Island Shv #8
RouteCity Street 0
CountySan Francisco County
StateCalifornia
Coordinates37.81011, -122.37128
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 rating31.1 US tons
Inventory rating18.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadUnknown
Structure length180 ft (54.9 m)
Longest span25 ft (7.6 m)
Deck width37 ft (11.3 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2020)
Projected traffic9,000 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 180 ft (54.9 m) long with a longest span of 25 ft (7.6 m) and a deck 37 ft wide.

Who owns Treasure Island RD over Sidehill?

It is owned by the County Highway Agency.