US Bridges

US Highway 101 SB over Healdsburg Avenue

Fair

Sonoma County, California · 04-SON-101-33.48 · Structure no. 20 0067L

Built
1962
63 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
246 ft
2 main spans
Daily traffic
22,750
2015 count
Owner
State
State Highway Agency

About this bridge

US Highway 101 SB over Healdsburg Avenue is a prestressed concrete stringer/multi-beam or girder carrying US Highway 101 SB over Healdsburg Avenue in Sonoma County, California. It was built in 1962, so it is 63 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 22,750 vehicles a day, roughly 13% of them trucks, projected to reach 44,170 by 2045. The structure is 246 ft (75 m) long and 40 ft wide.

Location

Open in Google Maps
CarriesUS Highway 101 SB
CrossesHealdsburg Avenue
Location04-SON-101-33.48
RouteU.S. Route 101
CountySonoma County
StateCalifornia
Coordinates38.59458, -122.85248
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionApril 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38.9 US tons
Inventory rating22.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length246 ft (75 m)
Longest span76 ft (23.2 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22,750 (2015)
Projected traffic44,170 by 2045
Trucks13%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 US Highway 101 SB over Healdsburg Avenue built?

It was built in 1962, making it 63 years old in 2025.

What condition is US Highway 101 SB over Healdsburg Avenue 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 US Highway 101 SB over Healdsburg Avenue carry?

About 22,750 vehicles per day (2015 count), of which roughly 13% are trucks.

How long is US Highway 101 SB over Healdsburg Avenue?

The structure is 246 ft (75 m) long with a longest span of 76 ft (23.2 m) and a deck 40 ft wide.

Who owns US Highway 101 SB over Healdsburg Avenue?

It is owned by the State Highway Agency.