US Bridges

I 90 over Madison Road

Fair

Gallatin County, Montana · 3.1M E Three Forks · Structure no. I00090280+03612

Built
1963
62 years old
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
128 ft
3 main spans
Daily traffic
9,762
2023 count
Owner
State
State Highway Agency

About this bridge

I 90 over Madison Road is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Madison Road in Gallatin County, Montana. It was built in 1963, so it is 62 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 9,762 vehicles a day, roughly 12% of them trucks, projected to reach 11,031 by 2043. The structure is 128 ft (39 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 90
CrossesMadison Road
Location3.1M E Three Forks
RouteInterstate 90
CountyGallatin County
StateMontana
Coordinates45.89552, -111.49365
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length128 ft (39 m)
Longest span45 ft (13.7 m)
Deck width41 ft (12.4 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,762 (2023)
Projected traffic11,031 by 2043
Trucks12%
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 over Madison Road built?

It was built in 1963, making it 62 years old in 2025.

What condition is I 90 over Madison 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 January 2024.

How much traffic does I 90 over Madison Road carry?

About 9,762 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is I 90 over Madison Road?

The structure is 128 ft (39 m) long with a longest span of 45 ft (13.7 m) and a deck 41 ft wide.

Who owns I 90 over Madison Road?

It is owned by the State Highway Agency.