US Bridges

Old HWY 20 over Parks Lewisville Canal

Fair

Jefferson County, Idaho · 1.2 N. 0.8 E. Rigby · Structure no. 000000000032645

Built
1939
86 years old
Condition
Fair
inspected March 2023
Type
Frame
Concrete
Length
20 ft
1 main span
Daily traffic
3,500
2023 count
Owner
County
County Highway Agency

About this bridge

Old HWY 20 over Parks Lewisville Canal is a concrete frame carrying Old HWY 20 over Parks Lewisville Canal in Jefferson County, Idaho. It was built in 1939, so it is 86 years old, older 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 3,500 vehicles a day, projected to reach 5,250 by 2042. The structure is 20 ft (6.1 m) long and 34 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesOld HWY 20
CrossesParks Lewisville Canal
Location1.2 N. 0.8 E. Rigby
RouteCounty Highway 0
CountyJefferson County
StateIdaho
Coordinates43.69003, -111.89783
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.
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 above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,500 (2023)
Projected traffic5,250 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway 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 Old HWY 20 over Parks Lewisville Canal built?

It was built in 1939, making it 86 years old in 2025.

What condition is Old HWY 20 over Parks Lewisville Canal 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 Old HWY 20 over Parks Lewisville Canal carry?

About 3,500 vehicles per day (2023 count).

How long is Old HWY 20 over Parks Lewisville Canal?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 34 ft wide.

Who owns Old HWY 20 over Parks Lewisville Canal?

It is owned by the County Highway Agency.