US Bridges

Road 99W over Hambright Creek

Good

Glenn County, California · 0.9 MI N of S.H. 32 · Structure no. 11C0195

Built
1936
89 years old
Condition
Good
inspected February 2025
Type
Tee Beam
Concrete Continuous
Length
100 ft
4 main spans
Daily traffic
3,301
2009 count
Owner
County
County Highway Agency

About this bridge

Road 99W over Hambright Creek is a concrete continuous tee beam carrying Road 99W over Hambright Creek in Glenn County, California. It was built in 1936, so it is 89 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 3,301 vehicles a day, roughly 10% of them trucks, projected to reach 5,978 by 2045. The structure is 100 ft (30.5 m) long and 40 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

CarriesRoad 99W
CrossesHambright Creek
Location0.9 MI N of S.H. 32
RouteCounty Highway 0
Coordinates39.76067, -122.19681
Functional classRural Major Collector

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 protection8 Very GoodNo problems noted.
Last inspectionFebruary 2025
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating28.9 US tons
Inventory rating22.2 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length100 ft (30.5 m)
Longest span29 ft (8.8 m)
Deck width40 ft (12.1 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,301 (2009)
Projected traffic5,978 by 2045
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 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 Road 99W over Hambright Creek built?

It was built in 1936, making it 89 years old in 2025.

What condition is Road 99W over Hambright 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 Road 99W over Hambright Creek carry?

About 3,301 vehicles per day (2009 count), of which roughly 10% are trucks.

How long is Road 99W over Hambright Creek?

The structure is 100 ft (30.5 m) long with a longest span of 29 ft (8.8 m) and a deck 40 ft wide.

Who owns Road 99W over Hambright Creek?

It is owned by the County Highway Agency.