US Bridges

STC8317;LANSING RD over Mill Slough

Fair

Canyon County, Idaho · 0.6 N. 2.4 E. Middleton · Structure no. 000000000027096

Built
1995
30 years old
Condition
Fair
inspected November 2023
Type
Frame
Concrete
Length
28 ft
1 main span
Daily traffic
2,400
2023 count
Owner
Local
Other Local Agency

About this bridge

STC8317;LANSING RD over Mill Slough is a concrete frame carrying STC8317;LANSING RD over Mill Slough in Canyon County, Idaho. It was built in 1995, so it is 30 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 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 2,400 vehicles a day, roughly 5% of them trucks, projected to reach 3,600 by 2042. The structure is 28 ft (8.5 m) long and 34 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSTC8317;LANSING RD
CrossesMill Slough
Location0.6 N. 2.4 E. Middleton
RouteCounty Highway 8317
CountyCanyon County
StateIdaho
Coordinates43.71406, -116.57269
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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating23 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length28 ft (8.5 m)
Longest span28 ft (8.5 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,400 (2023)
Projected traffic3,600 by 2042
Trucks5%
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 STC8317;LANSING RD over Mill Slough built?

It was built in 1995, making it 30 years old in 2025.

What condition is STC8317;LANSING RD over Mill Slough 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 November 2023.

How much traffic does STC8317;LANSING RD over Mill Slough carry?

About 2,400 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is STC8317;LANSING RD over Mill Slough?

The structure is 28 ft (8.5 m) long with a longest span of 28 ft (8.5 m) and a deck 34 ft wide.

Who owns STC8317;LANSING RD over Mill Slough?

It is owned by the Other Local Agency.