US Bridges

Illinois Street over Islais Creek

Fair

San Francisco County, California · 0.2 MI North of Cargo Way · Structure no. 34C0076

Built
2008
17 years old
Condition
Fair
inspected December 2023
Type
Movable - Bascule
Steel
Length
460 ft
1 main span
Daily traffic
2,000
2016 count
Owner
Local
Other Local Agency

About this bridge

Illinois Street over Islais Creek is a steel movable - bascule carrying Illinois Street over Islais Creek in San Francisco County, California. It was built in 2008, so it is 17 years old, younger 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 2,000 vehicles a day, roughly 40% of them trucks, projected to reach 3,053 by 2043. The structure is 460 ft (140.1 m) long and 38 ft wide.

Location

Open in Google Maps
CarriesIllinois Street
CrossesIslais Creek
Location0.2 MI North of Cargo Way
RouteCity Street 0
CountySan Francisco County
StateCalifornia
Coordinates37.74679, -122.38609
Functional classUrban Other Principal 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.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating62.5 US tons
Inventory rating37.5 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckOpen grating
Main spans1 (+7 approach)
Design loadHS 20
Structure length460 ft (140.1 m)
Longest span81 ft (24.7 m)
Deck width38 ft (11.5 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2016)
Projected traffic3,053 by 2043
Trucks40%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and railroad
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerOther Local Agency
Maintained byOther Local Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Illinois Street over Islais Creek built?

It was built in 2008, making it 17 years old in 2025.

What condition is Illinois Street over Islais Creek 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 December 2023.

How much traffic does Illinois Street over Islais Creek carry?

About 2,000 vehicles per day (2016 count), of which roughly 40% are trucks.

How long is Illinois Street over Islais Creek?

The structure is 460 ft (140.1 m) long with a longest span of 81 ft (24.7 m) and a deck 38 ft wide.

Who owns Illinois Street over Islais Creek?

It is owned by the Other Local Agency.