US Bridges

ST RTE 101 (5th ST over Bayshore Viaduct

Fair

San Francisco County, California · 04-SF-101-4.12-SF · Structure no. 34 0088

Built
1955
70 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
7,502 ft
8 main spans
Daily traffic
256,700
2019 count
Owner
State
State Highway Agency

About this bridge

ST RTE 101 (5th ST over Bayshore Viaduct is a steel stringer/multi-beam or girder carrying ST RTE 101 (5th ST over Bayshore Viaduct in San Francisco County, California. It was built in 1955, so it is 70 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 256,700 vehicles a day, roughly 4% of them trucks, projected to reach 375,401 by 2041. The structure is 7,502 ft (2,286.6 m) long and 80 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesST RTE 101 (5th ST
CrossesBayshore Viaduct
Location04-SF-101-4.12-SF
RouteU.S. Route 101
CountySan Francisco County
StateCalifornia
Coordinates37.76431, -122.40482
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment6: Equal to present minimum criteria
Operating rating50 US tons
Inventory rating28.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans8 (+247 approach)
Design loadHS 20
Structure length7,502 ft (2,286.6 m)
Longest span118 ft (36 m)
Deck width80 ft (24.4 m)
Roadway width76 ft (23.2 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic256,700 (2019)
Projected traffic375,401 by 2041
Trucks4%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.9 mi (3 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST RTE 101 (5th ST over Bayshore Viaduct built?

It was built in 1955, making it 70 years old in 2025.

What condition is ST RTE 101 (5th ST over Bayshore Viaduct 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 May 2023.

How much traffic does ST RTE 101 (5th ST over Bayshore Viaduct carry?

About 256,700 vehicles per day (2019 count), of which roughly 4% are trucks.

How long is ST RTE 101 (5th ST over Bayshore Viaduct?

The structure is 7,502 ft (2,286.6 m) long with a longest span of 118 ft (36 m) and a deck 80 ft wide.

Who owns ST RTE 101 (5th ST over Bayshore Viaduct?

It is owned by the State Highway Agency.