US Bridges

Shiloh Road over U.S. Highway 101

Fair

Sonoma County, California · 04-SON-101-27.62 · Structure no. 20 0202

Built
1962
63 years old
Condition
Fair
inspected August 2024
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
248 ft
4 main spans
Daily traffic
3,000
2018 count
Owner
State
State Highway Agency

About this bridge

Shiloh Road over U.S. Highway 101 is a concrete continuous box beam or girders - multiple carrying Shiloh Road over U.S. Highway 101 in Sonoma County, California. It was built in 1962, so it is 63 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 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 3,000 vehicles a day, roughly 7% of them trucks, projected to reach 5,256 by 2046. The structure is 248 ft (75.6 m) long and 40 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesShiloh Road
CrossesU.S. Highway 101
Location04-SON-101-27.62
RouteCity Street 0
Coordinates38.52578, -122.79049
Functional classUrban Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.7 US tons
Inventory rating33.6 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length248 ft (75.6 m)
Longest span84 ft (25.6 m)
Deck width40 ft (12.3 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2018)
Projected traffic5,256 by 2046
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

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 Shiloh Road over U.S. Highway 101 built?

It was built in 1962, making it 63 years old in 2025.

What condition is Shiloh Road over U.S. Highway 101 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 Shiloh Road over U.S. Highway 101 carry?

About 3,000 vehicles per day (2018 count), of which roughly 7% are trucks.

How long is Shiloh Road over U.S. Highway 101?

The structure is 248 ft (75.6 m) long with a longest span of 84 ft (25.6 m) and a deck 40 ft wide.

Who owns Shiloh Road over U.S. Highway 101?

It is owned by the State Highway Agency.