US Bridges

SH 16 over Middleton Canal

Fair

Ada County, Idaho · 14 S. Emmett · Structure no. 000000000012135

Built
1959
66 years old
Condition
Fair
inspected January 2025
Type
Tee Beam
Concrete
Length
30 ft
1 main span
Daily traffic
11,500
2023 count
Owner
State
State Highway Agency

About this bridge

SH 16 over Middleton Canal is a concrete tee beam carrying SH 16 over Middleton Canal in Ada County, Idaho. It was built in 1959, so it is 66 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 11,500 vehicles a day, roughly 5% of them trucks, projected to reach 17,250 by 2042. The structure is 30 ft (9.1 m) long and 36 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesSH 16
CrossesMiddleton Canal
Location14 S. Emmett
RouteState Highway 16
CountyAda County
StateIdaho
Coordinates43.70116, -116.45843
Functional classRural Principal Arterial - Other

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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
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 rating52 US tons
Inventory rating31 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span28 ft (8.5 m)
Deck width36 ft (11.1 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,500 (2023)
Projected traffic17,250 by 2042
Trucks5%
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

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$582,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 16 over Middleton Canal built?

It was built in 1959, making it 66 years old in 2025.

What condition is SH 16 over Middleton 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 January 2025.

How much traffic does SH 16 over Middleton Canal carry?

About 11,500 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is SH 16 over Middleton Canal?

The structure is 30 ft (9.1 m) long with a longest span of 28 ft (8.5 m) and a deck 36 ft wide.

Who owns SH 16 over Middleton Canal?

It is owned by the State Highway Agency.