US Bridges

Railroad Grade RD over St. Joe River

Fair

Benewah County, Idaho · 16.0 E. St. Maries · Structure no. 000000000037075

Built
1908
117 years old
Condition
Fair
inspected June 2024
Type
Truss - Thru
Steel
Length
448 ft
2 main spans
Daily traffic
40
2023 count
Owner
County
County Highway Agency

About this bridge

Railroad Grade RD over St. Joe River is a steel truss - thru carrying Railroad Grade RD over St. Joe River in Benewah County, Idaho. It was built in 1908, so it is 117 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 40 vehicles a day, roughly 5% of them trucks, projected to reach 60 by 2039. The structure is 448 ft (136.6 m) long and 16 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesRailroad Grade RD
CrossesSt. Joe River
Location16.0 E. St. Maries
RouteCounty Highway 0
CountyBenewah County
StateIdaho
Coordinates47.32161, -116.29169
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating110.1 US tons
Inventory rating87 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans2
Design loadH 15
Structure length448 ft (136.6 m)
Longest span150 ft (45.7 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deck19 ft (5.6 m)

Traffic and service

Average daily traffic40 (2023)
Projected traffic60 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.3 million (2018 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Railroad Grade RD over St. Joe River built?

It was built in 1908, making it 117 years old in 2025.

What condition is Railroad Grade RD over St. Joe River 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 June 2024.

How much traffic does Railroad Grade RD over St. Joe River carry?

About 40 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Railroad Grade RD over St. Joe River?

The structure is 448 ft (136.6 m) long with a longest span of 150 ft (45.7 m) and a deck 16 ft wide.

Who owns Railroad Grade RD over St. Joe River?

It is owned by the County Highway Agency.