US Bridges

SW Ash ST over Big Spring Creek

Fair

Fergus County, Montana · Lewistown-Sw Ash ST · Structure no. U07110000+03101

Built
1962
63 years old
Condition
Fair
inspected April 2023
Type
Slab
Prestressed Concrete
Length
52 ft
2 main spans
Daily traffic
1,394
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

SW Ash ST over Big Spring Creek is a prestressed concrete slab carrying SW Ash ST over Big Spring Creek in Fergus County, Montana. It was built in 1962, so it is 63 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 5 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 1,394 vehicles a day, roughly 1% of them trucks, projected to reach 1,464 by 2043. The structure is 52 ft (15.8 m) long and 23 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSW Ash ST
CrossesBig Spring Creek
LocationLewistown-Sw Ash ST
RouteCity Street 7110
CountyFergus County
StateMontana
Coordinates47.05191, -109.41947
Functional classUrban Collector

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating42.1 US tons
Inventory rating30.3 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadHS 20
Structure length52 ft (15.8 m)
Longest span25 ft (7.6 m)
Deck width23 ft (6.9 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,394 (2023)
Projected traffic1,464 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$105,000
NavigationNo navigation control on waterway

Frequently asked questions

When was SW Ash ST over Big Spring Creek built?

It was built in 1962, making it 63 years old in 2025.

What condition is SW Ash ST over Big Spring Creek 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 April 2023.

How much traffic does SW Ash ST over Big Spring Creek carry?

About 1,394 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is SW Ash ST over Big Spring Creek?

The structure is 52 ft (15.8 m) long with a longest span of 25 ft (7.6 m) and a deck 23 ft wide.

Who owns SW Ash ST over Big Spring Creek?

It is owned by the City or Municipal Highway Agency.