US Bridges

I 15 over RR

Good

Pondera County, Montana · 2M N Conrad · Structure no. I00015341+09252

Built
1972
53 years old
Condition
Good
inspected December 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
165 ft
3 main spans
Daily traffic
1,727
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over RR is a prestressed concrete stringer/multi-beam or girder carrying I 15 over RR in Pondera County, Montana. It was built in 1972, so it is 53 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 1,727 vehicles a day, roughly 24% of them trucks, projected to reach 1,813 by 2043. The structure is 165 ft (50.3 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI 15
CrossesRR
Location2M N Conrad
RouteInterstate 15
StateMontana
Coordinates48.21587, -111.93259
Functional classRural 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
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating38 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length165 ft (50.3 m)
Longest span72 ft (21.8 m)
Deck width44 ft (13.5 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,727 (2023)
Projected traffic1,813 by 2043
Trucks24%
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 I 15 over RR built?

It was built in 1972, making it 53 years old in 2025.

What condition is I 15 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 December 2024.

How much traffic does I 15 over RR carry?

About 1,727 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 15 over RR?

The structure is 165 ft (50.3 m) long with a longest span of 72 ft (21.8 m) and a deck 44 ft wide.

Who owns I 15 over RR?

It is owned by the State Highway Agency.