US Bridges

Westside Road over Dry Creek

Fair

Sonoma County, California · 0.5 MI West of US 101 · Structure no. 20C0040

Built
1934
91 years old
Condition
Fair
inspected October 2024
Type
Truss - Thru
Steel
Length
330 ft
4 main spans
Daily traffic
6,100
2015 count
Owner
County
County Highway Agency

About this bridge

Westside Road over Dry Creek is a steel truss - thru carrying Westside Road over Dry Creek in Sonoma County, California. It was built in 1934, so it is 91 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 6,100 vehicles a day, roughly 2% of them trucks, projected to reach 7,285 by 2046. The structure is 330 ft (100.6 m) long and 25 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesWestside Road
CrossesDry Creek
Location0.5 MI West of US 101
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.60435, -122.88294
Functional classRural Major Collector

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.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.6 US tons
Inventory rating20.7 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length330 ft (100.6 m)
Longest span82 ft (25 m)
Deck width25 ft (7.7 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,100 (2015)
Projected traffic7,285 by 2046
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed11.2 mi (18 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Westside Road over Dry Creek built?

It was built in 1934, making it 91 years old in 2025.

What condition is Westside Road over Dry 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 October 2024.

How much traffic does Westside Road over Dry Creek carry?

About 6,100 vehicles per day (2015 count), of which roughly 2% are trucks.

How long is Westside Road over Dry Creek?

The structure is 330 ft (100.6 m) long with a longest span of 82 ft (25 m) and a deck 25 ft wide.

Who owns Westside Road over Dry Creek?

It is owned by the County Highway Agency.