US Bridges

Island RD over Scott River Overflow

Fair

Siskiyou County, California · 0.3 MI E Serpa Lane · Structure no. 02C0081

Built
1986
39 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete Continuous
Length
84 ft
3 main spans
Daily traffic
170
2011 count
Owner
County
County Highway Agency

About this bridge

Island RD over Scott River Overflow is a concrete continuous slab carrying Island RD over Scott River Overflow in Siskiyou County, California. It was built in 1986, so it is 39 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 170 vehicles a day, roughly 12% of them trucks, projected to reach 463 by 2042. The structure is 84 ft (25.6 m) long and 25 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesIsland RD
CrossesScott River Overflow
Location0.3 MI E Serpa Lane
RouteCounty Highway 0
CountySiskiyou County
StateCalifornia
Coordinates41.57038, -122.84673
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length84 ft (25.6 m)
Longest span28 ft (8.5 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic170 (2011)
Projected traffic463 by 2042
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 Island RD over Scott River Overflow built?

It was built in 1986, making it 39 years old in 2025.

What condition is Island RD over Scott River Overflow 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 June 2024.

How much traffic does Island RD over Scott River Overflow carry?

About 170 vehicles per day (2011 count), of which roughly 12% are trucks.

How long is Island RD over Scott River Overflow?

The structure is 84 ft (25.6 m) long with a longest span of 28 ft (8.5 m) and a deck 25 ft wide.

Who owns Island RD over Scott River Overflow?

It is owned by the County Highway Agency.