US Bridges

I 15 over Int 1st ST NE

Fair

Toole County, Montana · Sunburst · Structure no. I00015389+08152

Built
1961
64 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
170 ft
3 main spans
Daily traffic
955
2023 count
Owner
State
State Highway Agency

About this bridge

I 15 over Int 1st ST NE is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Int 1st ST NE in Toole County, Montana. It was built in 1961, so it is 64 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 955 vehicles a day, roughly 40% of them trucks, projected to reach 1,003 by 2043. The structure is 170 ft (51.8 m) long and 30 ft wide.

Location

Open in Google Maps
CarriesI 15
CrossesInt 1st ST NE
LocationSunburst
RouteInterstate 15
CountyToole County
StateMontana
Coordinates48.8849, -111.90348
Functional classRural Principal Arterial - Interstate

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment7: Better than present minimum criteria
Operating rating68 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length170 ft (51.8 m)
Longest span67 ft (20.3 m)
Deck width30 ft (9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic955 (2023)
Projected traffic1,003 by 2043
Trucks40%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed—
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$352,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 15 over Int 1st ST NE built?

It was built in 1961, making it 64 years old in 2025.

What condition is I 15 over Int 1st ST NE 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 November 2023.

How much traffic does I 15 over Int 1st ST NE carry?

About 955 vehicles per day (2023 count), of which roughly 40% are trucks.

How long is I 15 over Int 1st ST NE?

The structure is 170 ft (51.8 m) long with a longest span of 67 ft (20.3 m) and a deck 30 ft wide.

Who owns I 15 over Int 1st ST NE?

It is owned by the State Highway Agency.