US Bridges

North Redwood HWY over Ncrra (old Nwp Rr)

Fair

Sonoma County, California · 04-SON-101-R54.28 · Structure no. 20 0032Y

Built
1985
40 years old
Condition
Fair
inspected May 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
219 ft
3 main spans
Daily traffic
1,000
2015 count
Owner
State
State Highway Agency

About this bridge

North Redwood HWY over Ncrra (old Nwp Rr) is a prestressed concrete continuous box beam or girders - multiple carrying North Redwood HWY over Ncrra (old Nwp Rr) in Sonoma County, California. It was built in 1985, so it is 40 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 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 1,000 vehicles a day, roughly 15% of them trucks, projected to reach 3,218 by 2045. The structure is 219 ft (66.8 m) long and 43 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

Open in Google Maps
CarriesNorth Redwood HWY
CrossesNcrra (old Nwp Rr)
Location04-SON-101-R54.28
RouteU.S. Route 101
CountySonoma County
StateCalifornia
Coordinates38.8285, -123.01364
Functional classUrban Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
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 geometry7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length219 ft (66.8 m)
Longest span75 ft (22.9 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,000 (2015)
Projected traffic3,218 by 2045
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed49.7 mi (80 km)
TollOn a free road
National Highway SystemNo
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 North Redwood HWY over Ncrra (old Nwp Rr) built?

It was built in 1985, making it 40 years old in 2025.

What condition is North Redwood HWY over Ncrra (old Nwp Rr) 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 May 2023.

How much traffic does North Redwood HWY over Ncrra (old Nwp Rr) carry?

About 1,000 vehicles per day (2015 count), of which roughly 15% are trucks.

How long is North Redwood HWY over Ncrra (old Nwp Rr)?

The structure is 219 ft (66.8 m) long with a longest span of 75 ft (22.9 m) and a deck 43 ft wide.

Who owns North Redwood HWY over Ncrra (old Nwp Rr)?

It is owned by the State Highway Agency.