US Bridges

Odonnell Lane over Calabazas Creek

FairPosted for load

Sonoma County, California · Near Arnold Drive · Structure no. 20C0324

Built
1900
125 years old
Condition
Fair
inspected April 2024
Type
Arch - Deck
Masonry
Length
40 ft
1 main span
Daily traffic
500
2015 count
Owner
County
County Highway Agency

About this bridge

Odonnell Lane over Calabazas Creek is a masonry arch - deck carrying Odonnell Lane over Calabazas Creek in Sonoma County, California. It was built in 1900, so it is 125 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. Its operating status is: posted for load restriction.

It carries about 500 vehicles a day, roughly 1% of them trucks, projected to reach 855 by 2046. The structure is 40 ft (12.2 m) long and 12 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesOdonnell Lane
CrossesCalabazas Creek
LocationNear Arnold Drive
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.36342, -122.52539
Functional classUrban Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 12 months
Operating statusPosted for load 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckNot applicable
Main spans1
Design loadUnknown
Structure length40 ft (12.2 m)
Longest span40 ft (12.2 m)
Deck width12 ft (3.7 m)
Roadway width10 ft (3.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic500 (2015)
Projected traffic855 by 2046
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Odonnell Lane over Calabazas Creek built?

It was built in 1900, making it 125 years old in 2025.

What condition is Odonnell Lane over Calabazas 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 April 2024.

How much traffic does Odonnell Lane over Calabazas Creek carry?

About 500 vehicles per day (2015 count), of which roughly 1% are trucks.

How long is Odonnell Lane over Calabazas Creek?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m) and a deck 12 ft wide.

Who owns Odonnell Lane over Calabazas Creek?

It is owned by the County Highway Agency.