US Bridges

129th South Road over Idaho Canal

FairPosted for load

Bonneville County, Idaho · 0.3 E. Taylorville · Structure no. 000000000031060

Built
1952
73 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
31 ft
1 main span
Daily traffic
960
2023 count
Owner
County
County Highway Agency

About this bridge

129th South Road over Idaho Canal is a steel stringer/multi-beam or girder carrying 129th South Road over Idaho Canal in Bonneville County, Idaho. It was built in 1952, so it is 73 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. Its operating status is: posted for load restriction.

It carries about 960 vehicles a day, roughly 1% of them trucks, projected to reach 1,440 by 2042. The structure is 31 ft (9.4 m) long and 28 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
Carries129th South Road
CrossesIdaho Canal
Location0.3 E. Taylorville
RouteCounty Highway 0
CountyBonneville County
StateIdaho
Coordinates43.38117, -112.02589
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating6 US tons
Inventory rating4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 10
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width28 ft (8.5 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic960 (2023)
Projected traffic1,440 by 2042
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$421,000 (2017 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 129th South Road over Idaho Canal built?

It was built in 1952, making it 73 years old in 2025.

What condition is 129th South Road over Idaho 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 129th South Road over Idaho Canal carry?

About 960 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is 129th South Road over Idaho Canal?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 28 ft wide.

Who owns 129th South Road over Idaho Canal?

It is owned by the County Highway Agency.