US Bridges

Jamison RD over Matanzas Creek

Fair

Sonoma County, California · 0.4 MI E Sonoma Mtn RD · Structure no. 20C0263

Built
1969
56 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
61 ft
1 main span
Daily traffic
150
2015 count
Owner
County
County Highway Agency

About this bridge

Jamison RD over Matanzas Creek is a steel stringer/multi-beam or girder carrying Jamison RD over Matanzas Creek in Sonoma County, California. It was built in 1969, so it is 56 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 150 vehicles a day, roughly 1% of them trucks, projected to reach 129 by 2046. The structure is 61 ft (18.6 m) long and 20 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesJamison RD
CrossesMatanzas Creek
Location0.4 MI E Sonoma Mtn RD
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.39218, -122.62037
Functional classRural Local

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34 US tons
Inventory rating26.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length61 ft (18.6 m)
Longest span57 ft (17.4 m)
Deck width20 ft (6.2 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic150 (2015)
Projected traffic129 by 2046
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Jamison RD over Matanzas Creek built?

It was built in 1969, making it 56 years old in 2025.

What condition is Jamison RD over Matanzas 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 2024.

How much traffic does Jamison RD over Matanzas Creek carry?

About 150 vehicles per day (2015 count), of which roughly 1% are trucks.

How long is Jamison RD over Matanzas Creek?

The structure is 61 ft (18.6 m) long with a longest span of 57 ft (17.4 m) and a deck 20 ft wide.

Who owns Jamison RD over Matanzas Creek?

It is owned by the County Highway Agency.