US Bridges

Ely RD over Willow Brook

Fair

Sonoma County, California · 0.1 MI SE Old Rdwd HWY N · Structure no. 20C0038

Built
1959
66 years old
Condition
Fair
inspected November 2024
Type
Slab
Concrete Continuous
Length
73 ft
3 main spans
Daily traffic
3,500
2015 count
Owner
County
County Highway Agency

About this bridge

Ely RD over Willow Brook is a concrete continuous slab carrying Ely RD over Willow Brook in Sonoma County, California. It was built in 1959, so it is 66 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 3,500 vehicles a day, roughly 5% of them trucks, projected to reach 4,268 by 2042. The structure is 73 ft (22.1 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesEly RD
CrossesWillow Brook
Location0.1 MI SE Old Rdwd HWY N
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.28317, -122.66626
Functional classUrban 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
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 protection7 GoodSome minor problems.
Last inspectionNovember 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating67.5 US tons
Inventory rating40.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length73 ft (22.1 m)
Longest span28 ft (8.5 m)
Deck width32 ft (9.9 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,500 (2015)
Projected traffic4,268 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Ely RD over Willow Brook built?

It was built in 1959, making it 66 years old in 2025.

What condition is Ely RD over Willow Brook 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 November 2024.

How much traffic does Ely RD over Willow Brook carry?

About 3,500 vehicles per day (2015 count), of which roughly 5% are trucks.

How long is Ely RD over Willow Brook?

The structure is 73 ft (22.1 m) long with a longest span of 28 ft (8.5 m) and a deck 32 ft wide.

Who owns Ely RD over Willow Brook?

It is owned by the County Highway Agency.