US Bridges

State Route 1 over Howard Creek

Good

Mendocino County, California · 01-MEN-001-R80.55 · Structure no. 10 0139

Built
1972
53 years old
Condition
Good
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
467 ft
5 main spans
Daily traffic
1,185
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Howard Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying State Route 1 over Howard Creek in Mendocino County, California. It was built in 1972, so it is 53 years old, younger 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 1,185 vehicles a day, roughly 3% of them trucks, projected to reach 1,020 by 2043. The structure is 467 ft (142.3 m) long and 42 ft wide. If it were closed, the detour would be 60.9 mi (98 km).

CarriesState Route 1
CrossesHoward Creek
Location01-MEN-001-R80.55
RouteState Highway 1
Coordinates39.67729, -123.78983
Functional classRural Minor Arterial

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 inspectionSeptember 2023
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 geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.1 US tons
Inventory rating22.5 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length467 ft (142.3 m)
Longest span93 ft (28.3 m)
Deck width42 ft (12.8 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,185 (2009)
Projected traffic1,020 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed60.9 mi (98 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 State Route 1 over Howard Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is State Route 1 over Howard 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 September 2023.

How much traffic does State Route 1 over Howard Creek carry?

About 1,185 vehicles per day (2009 count), of which roughly 3% are trucks.

How long is State Route 1 over Howard Creek?

The structure is 467 ft (142.3 m) long with a longest span of 93 ft (28.3 m) and a deck 42 ft wide.

Who owns State Route 1 over Howard Creek?

It is owned by the State Highway Agency.