US Bridges

U.S. Highway 101 over Marion Lane

Fair

Mendocino County, California · 01-MEN-101-R88.80 · Structure no. 10 0228

Built
1970
55 years old
Condition
Fair
inspected April 2024
Type
Box Beam or Girders - Multiple
Concrete
Length
88 ft
1 main span
Daily traffic
6,100
2009 count
Owner
State
State Highway Agency

About this bridge

U.S. Highway 101 over Marion Lane is a concrete box beam or girders - multiple carrying U.S. Highway 101 over Marion Lane in Mendocino County, California. It was built in 1970, so it is 55 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 6,100 vehicles a day, roughly 16% of them trucks, projected to reach 8,263 by 2042. The structure is 88 ft (26.8 m) long and 74 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

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CarriesU.S. Highway 101
CrossesMarion Lane
Location01-MEN-101-R88.80
RouteU.S. Route 101
CountyMendocino County
StateCalifornia
Coordinates39.84368, -123.69461
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44 US tons
Inventory rating34 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length88 ft (26.8 m)
Longest span86 ft (26.2 m)
Deck width74 ft (22.6 m)
Roadway width72 ft (21.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,100 (2009)
Projected traffic8,263 by 2042
Trucks16%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed31.7 mi (51 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was U.S. Highway 101 over Marion Lane built?

It was built in 1970, making it 55 years old in 2025.

What condition is U.S. Highway 101 over Marion Lane 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 2024.

How much traffic does U.S. Highway 101 over Marion Lane carry?

About 6,100 vehicles per day (2009 count), of which roughly 16% are trucks.

How long is U.S. Highway 101 over Marion Lane?

The structure is 88 ft (26.8 m) long with a longest span of 86 ft (26.2 m) and a deck 74 ft wide.

Who owns U.S. Highway 101 over Marion Lane?

It is owned by the State Highway Agency.