US Bridges

Stc 3730;RIVERSIDE over Deer Flat High Line Cnl

Fair

Canyon County, Idaho · 1.8 N. 3.3 E. Marsing · Structure no. 000000000019690

Built
1986
39 years old
Condition
Fair
inspected March 2023
Type
Frame
Concrete
Length
27 ft
1 main span
Daily traffic
980
2023 count
Owner
Local
Other Local Agency

About this bridge

Stc 3730;RIVERSIDE over Deer Flat High Line Cnl is a concrete frame carrying Stc 3730;RIVERSIDE over Deer Flat High Line Cnl in Canyon County, Idaho. It was built in 1986, so it is 39 years old, younger than the Idaho average of 45.3 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 980 vehicles a day, roughly 21% of them trucks, projected to reach 1,470 by 2042. The structure is 27 ft (8.2 m) long and 33 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesStc 3730;RIVERSIDE
CrossesDeer Flat High Line Cnl
Location1.8 N. 3.3 E. Marsing
RouteCounty Highway 3730
CountyCanyon County
StateIdaho
Coordinates43.57314, -116.74783
Functional classRural Major 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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52 US tons
Inventory rating31 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span27 ft (8.2 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic980 (2023)
Projected traffic1,470 by 2042
Trucks21%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerOther Local Agency
Maintained byOther Local Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Stc 3730;RIVERSIDE over Deer Flat High Line Cnl built?

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

What condition is Stc 3730;RIVERSIDE over Deer Flat High Line Cnl 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 March 2023.

How much traffic does Stc 3730;RIVERSIDE over Deer Flat High Line Cnl carry?

About 980 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is Stc 3730;RIVERSIDE over Deer Flat High Line Cnl?

The structure is 27 ft (8.2 m) long with a longest span of 27 ft (8.2 m) and a deck 33 ft wide.

Who owns Stc 3730;RIVERSIDE over Deer Flat High Line Cnl?

It is owned by the Other Local Agency.