US Bridges

Offramp NB RTE 101 over Mark West Creek

Fair

Sonoma County, California · 04-SON-101-26.12 · Structure no. 20 0298S

Built
2014
11 years old
Condition
Fair
inspected August 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
135 ft
1 main span
Daily traffic
10,000
2014 count
Owner
State
State Highway Agency

About this bridge

Offramp NB RTE 101 over Mark West Creek is a prestressed concrete box beam or girders - multiple carrying Offramp NB RTE 101 over Mark West Creek in Sonoma County, California. It was built in 2014, so it is 11 years old, younger 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 6 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 10,000 vehicles a day, roughly 6% of them trucks, projected to reach 12,283 by 2044. The structure is 135 ft (41.2 m) long and 39 ft wide. If it were closed, the detour would be 4.3 mi (7 km).

Location

Open in Google Maps
CarriesOfframp NB RTE 101
CrossesMark West Creek
Location04-SON-101-26.12
RouteU.S. Route 101
CountySonoma County
StateCalifornia
Coordinates38.50906, -122.77204
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating92.8 US tons
Inventory rating64.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length135 ft (41.2 m)
Longest span135 ft (41.2 m)
Deck width39 ft (11.9 m)
Roadway width34 ft (10.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,000 (2014)
Projected traffic12,283 by 2044
Trucks6%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed4.3 mi (7 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 Offramp NB RTE 101 over Mark West Creek built?

It was built in 2014, making it 11 years old in 2025.

What condition is Offramp NB RTE 101 over Mark West 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 August 2024.

How much traffic does Offramp NB RTE 101 over Mark West Creek carry?

About 10,000 vehicles per day (2014 count), of which roughly 6% are trucks.

How long is Offramp NB RTE 101 over Mark West Creek?

The structure is 135 ft (41.2 m) long with a longest span of 135 ft (41.2 m) and a deck 39 ft wide.

Who owns Offramp NB RTE 101 over Mark West Creek?

It is owned by the State Highway Agency.