US Bridges

Old HWY 91 over Uprr;n.Spencer RR Op

Poor

Clark County, Idaho · 13.1 N. 5.2 W. Spencer · Structure no. 000000000031565

Built
1936
89 years old
Condition
Poor
inspected July 2024
Type
Truss - Thru
Steel
Length
296 ft
1 main span
Daily traffic
50
2023 count
Owner
County
County Highway Agency

About this bridge

Old HWY 91 over Uprr;n.Spencer RR Op is a steel truss - thru carrying Old HWY 91 over Uprr;n.Spencer RR Op in Clark County, Idaho. It was built in 1936, so it is 89 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 50 vehicles a day, roughly 10% of them trucks, projected to reach 75 by 2039. The structure is 296 ft (90.2 m) long and 25 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesOld HWY 91
CrossesUprr;n.Spencer RR Op
Location13.1 N. 5.2 W. Spencer
RouteCounty Highway 0
CountyClark County
StateIdaho
Coordinates44.54917, -112.29614
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating46 US tons
Inventory rating27 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadH 15
Structure length296 ft (90.2 m)
Longest span161 ft (49.1 m)
Deck width25 ft (7.7 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deck15 ft (4.4 m)

Traffic and service

Average daily traffic50 (2023)
Projected traffic75 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Old HWY 91 over Uprr;n.Spencer RR Op built?

It was built in 1936, making it 89 years old in 2025.

What condition is Old HWY 91 over Uprr;n.Spencer RR Op in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2024.

How much traffic does Old HWY 91 over Uprr;n.Spencer RR Op carry?

About 50 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Old HWY 91 over Uprr;n.Spencer RR Op?

The structure is 296 ft (90.2 m) long with a longest span of 161 ft (49.1 m) and a deck 25 ft wide.

Who owns Old HWY 91 over Uprr;n.Spencer RR Op?

It is owned by the County Highway Agency.