US Bridges

100 West ST over St. Charles CR N. Bridge

Fair

Bear Lake County, Idaho · In City of St. Charles · Structure no. 000000000022259

Built
1920
105 years old, rebuilt 1931
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
31 ft
1 main span
Daily traffic
50
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

100 West ST over St. Charles CR N. Bridge is a steel stringer/multi-beam or girder carrying 100 West ST over St. Charles CR N. Bridge in Bear Lake County, Idaho. It was built in 1920 and reconstructed in 1931, so it is 105 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.

It carries about 50 vehicles a day, roughly 5% of them trucks, projected to reach 75 by 2039. The structure is 31 ft (9.4 m) long and 28 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
Carries100 West ST
CrossesSt. Charles CR N. Bridge
LocationIn City of St. Charles
RouteCounty Highway 0
CountyBear Lake County
StateIdaho
Coordinates42.12386, -111.39161
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45 US tons
Inventory rating27 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2023)
Projected traffic75 by 2039
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$330,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 100 West ST over St. Charles CR N. Bridge built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1931.

What condition is 100 West ST over St. Charles CR N. Bridge 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 September 2024.

How much traffic does 100 West ST over St. Charles CR N. Bridge carry?

About 50 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is 100 West ST over St. Charles CR N. Bridge?

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 100 West ST over St. Charles CR N. Bridge?

It is owned by the City or Municipal Highway Agency.