US Bridges

SH 77 over G Canal

Fair

Cassia County, Idaho · 1.1 N. Declo · Structure no. 000000000015245

Built
1950
75 years old
Condition
Fair
inspected March 2023
Type
Frame
Concrete
Length
24 ft
1 main span
Daily traffic
3,200
2023 count
Owner
State
State Highway Agency

About this bridge

SH 77 over G Canal is a concrete frame carrying SH 77 over G Canal in Cassia County, Idaho. It was built in 1950, so it is 75 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 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 3,200 vehicles a day, roughly 4% of them trucks, projected to reach 4,800 by 2042. The structure is 24 ft (7.3 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSH 77
CrossesG Canal
Location1.1 N. Declo
RouteState Highway 77
CountyCassia County
StateIdaho
Coordinates42.53653, -113.62831
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
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 evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating49.1 US tons
Inventory rating29 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length24 ft (7.3 m)
Longest span24 ft (7.3 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2023)
Projected traffic4,800 by 2042
Trucks4%
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

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$457,000 (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 77 over G Canal built?

It was built in 1950, making it 75 years old in 2025.

What condition is SH 77 over G 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 SH 77 over G Canal carry?

About 3,200 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is SH 77 over G Canal?

The structure is 24 ft (7.3 m) long with a longest span of 24 ft (7.3 m) and a deck 28 ft wide.

Who owns SH 77 over G Canal?

It is owned by the State Highway Agency.