US Bridges

Manor Lane over Adobe Creek

Good

Sonoma County, California · 0.77 MI N Adobe RD · Structure no. 20C0307

Built
1960
65 years old
Condition
Good
inspected February 2025
Type
Slab
Concrete
Length
32 ft
1 main span
Daily traffic
150
2011 count
Owner
County
County Highway Agency

About this bridge

Manor Lane over Adobe Creek is a concrete slab carrying Manor Lane over Adobe Creek in Sonoma County, California. It was built in 1960, so it is 65 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 150 vehicles a day, roughly 6% of them trucks, projected to reach 138 by 2047. The structure is 32 ft (9.8 m) long and 25 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesManor Lane
CrossesAdobe Creek
Location0.77 MI N Adobe RD
RouteCounty Highway 0
Coordinates38.26588, -122.58192
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating38.3 US tons
Inventory rating22.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length32 ft (9.8 m)
Longest span32 ft (9.8 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic150 (2011)
Projected traffic138 by 2047
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Manor Lane over Adobe Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Manor Lane over Adobe Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2025.

How much traffic does Manor Lane over Adobe Creek carry?

About 150 vehicles per day (2011 count), of which roughly 6% are trucks.

How long is Manor Lane over Adobe Creek?

The structure is 32 ft (9.8 m) long with a longest span of 32 ft (9.8 m) and a deck 25 ft wide.

Who owns Manor Lane over Adobe Creek?

It is owned by the County Highway Agency.