US Bridges

US Highway 101 NB over Robinson Creek

Fair

Mendocino County, California · 01-MEN-101-20.91 · Structure no. 10 0005R

Built
1963
62 years old
Condition
Fair
inspected April 2023
Type
Tee Beam
Concrete Continuous
Length
146 ft
4 main spans
Daily traffic
7,350
2009 count
Owner
State
State Highway Agency

About this bridge

US Highway 101 NB over Robinson Creek is a concrete continuous tee beam carrying US Highway 101 NB over Robinson Creek in Mendocino County, California. It was built in 1963, so it is 62 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.

It carries about 7,350 vehicles a day, projected to reach 11,630 by 2043. The structure is 146 ft (44.5 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS Highway 101 NB
CrossesRobinson Creek
Location01-MEN-101-20.91
RouteU.S. Route 101
CountyMendocino County
StateCalifornia
Coordinates39.09995, -123.19104
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 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 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 rating42.1 US tons
Inventory rating30 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length146 ft (44.5 m)
Longest span36 ft (11 m)
Deck width40 ft (12.2 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,350 (2009)
Projected traffic11,630 by 2043
Trucks0%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 US Highway 101 NB over Robinson Creek built?

It was built in 1963, making it 62 years old in 2025.

What condition is US Highway 101 NB over Robinson 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 2023.

How much traffic does US Highway 101 NB over Robinson Creek carry?

About 7,350 vehicles per day (2009 count).

How long is US Highway 101 NB over Robinson Creek?

The structure is 146 ft (44.5 m) long with a longest span of 36 ft (11 m) and a deck 40 ft wide.

Who owns US Highway 101 NB over Robinson Creek?

It is owned by the State Highway Agency.