US Bridges

Branch I 15-U.S. 8 over RR

Good

Cascade County, Montana · Great Falls · Structure no. I00315001+00692

Built
1967
58 years old, rebuilt 1996
Condition
Good
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
208 ft
1 main span
Daily traffic
6,326
2023 count
Owner
State
State Highway Agency

About this bridge

Branch I 15-U.S. 8 over RR is a steel stringer/multi-beam or girder carrying Branch I 15-U.S. 8 over RR in Cascade County, Montana. It was built in 1967 and reconstructed in 1996, so it is 58 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 6,326 vehicles a day, roughly 5% of them trucks, projected to reach 6,642 by 2043. The structure is 208 ft (63.4 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesBranch I 15-U.S. 8
CrossesRR
LocationGreat Falls
RouteInterstate 315
CountyCascade County
StateMontana
Coordinates47.48794, -111.33528
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.2 US tons
Inventory rating37.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+4 approach)
Design loadHS 20
Structure length208 ft (63.4 m)
Longest span52 ft (15.7 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,326 (2023)
Projected traffic6,642 by 2043
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Branch I 15-U.S. 8 over RR built?

It was built in 1967, making it 58 years old in 2025. It was reconstructed in 1996.

What condition is Branch I 15-U.S. 8 over RR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2023.

How much traffic does Branch I 15-U.S. 8 over RR carry?

About 6,326 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Branch I 15-U.S. 8 over RR?

The structure is 208 ft (63.4 m) long with a longest span of 52 ft (15.7 m) and a deck 40 ft wide.

Who owns Branch I 15-U.S. 8 over RR?

It is owned by the State Highway Agency.