US Bridges

Hill Road over Mill Creek

PoorPosted for load

Mendocino County, California · 2.0 MI E Fairbanks RD · Structure no. 10C0111

Built
1925
100 years old
Condition
Poor
inspected August 2024
Type
Truss - Thru
Steel
Length
123 ft
1 main span
Daily traffic
78
2014 count
Owner
County
County Highway Agency

About this bridge

Hill Road over Mill Creek is a steel truss - thru carrying Hill Road over Mill Creek in Mendocino County, California. It was built in 1925, so it is 100 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 78 vehicles a day, roughly 2% of them trucks, projected to reach 272 by 2041. The structure is 123 ft (37.5 m) long and 18 ft wide. If it were closed, the detour would be 13 mi (21 km).

CarriesHill Road
CrossesMill Creek
Location2.0 MI E Fairbanks RD
RouteCounty Highway 0
Coordinates39.74907, -123.18157
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating12.1 US tons
Inventory rating7.2 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length123 ft (37.5 m)
Longest span120 ft (36.6 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.3 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic78 (2014)
Projected traffic272 by 2041
Trucks2%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$795,000 (2017 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Hill Road over Mill Creek built?

It was built in 1925, making it 100 years old in 2025.

What condition is Hill Road over Mill Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2024.

How much traffic does Hill Road over Mill Creek carry?

About 78 vehicles per day (2014 count), of which roughly 2% are trucks.

How long is Hill Road over Mill Creek?

The structure is 123 ft (37.5 m) long with a longest span of 120 ft (36.6 m) and a deck 18 ft wide.

Who owns Hill Road over Mill Creek?

It is owned by the County Highway Agency.