US Bridges

I 90 EB over Sep Rustic Road

Fair

Missoula County, Montana · 1.2M E Bonner · Structure no. I00090111+06571

Built
1964
61 years old, rebuilt 1999
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
120 ft
3 main spans
Daily traffic
6,216
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 EB over Sep Rustic Road is a prestressed concrete stringer/multi-beam or girder carrying I 90 EB over Sep Rustic Road in Missoula County, Montana. It was built in 1964 and reconstructed in 1999, so it is 61 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 6,216 vehicles a day, roughly 19% of them trucks, projected to reach 6,526 by 2043. The structure is 120 ft (36.5 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90 EB
CrossesSep Rustic Road
Location1.2M E Bonner
RouteInterstate 90
CountyMissoula County
StateMontana
Coordinates46.85918, -113.86237
Functional classUrban 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.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to 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 rating46 US tons
Inventory rating28 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length120 ft (36.5 m)
Longest span47 ft (14.3 m)
Deck width40 ft (12.2 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,216 (2023)
Projected traffic6,526 by 2043
Trucks19%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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 90 EB over Sep Rustic Road built?

It was built in 1964, making it 61 years old in 2025. It was reconstructed in 1999.

What condition is I 90 EB over Sep Rustic Road 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 I 90 EB over Sep Rustic Road carry?

About 6,216 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is I 90 EB over Sep Rustic Road?

The structure is 120 ft (36.5 m) long with a longest span of 47 ft (14.3 m) and a deck 40 ft wide.

Who owns I 90 EB over Sep Rustic Road?

It is owned by the State Highway Agency.