US Bridges

Frontage Rd-S 205 over Drainage

Fair

Gallatin County, Montana · 2M NW Manhattan · Structure no. S00205008+03441

Built
1931
94 years old
Condition
Fair
inspected April 2024
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
1,162
2023 count
Owner
State
State Highway Agency

About this bridge

Frontage Rd-S 205 over Drainage is a concrete slab carrying Frontage Rd-S 205 over Drainage in Gallatin County, Montana. It was built in 1931, so it is 94 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 1,162 vehicles a day, roughly 2% of them trucks, projected to reach 1,220 by 2043. The structure is 23 ft (7 m) long and 25 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesFrontage Rd-S 205
CrossesDrainage
Location2M NW Manhattan
RouteState Highway 205
CountyGallatin County
StateMontana
Coordinates45.8783, -111.37395
Functional classRural Major 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 protection8 Very GoodNo problems noted.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 alignment8: Equal to present desirable criteria
Operating rating31 US tons
Inventory rating24 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length23 ft (7 m)
Longest span22 ft (6.6 m)
Deck width25 ft (7.7 m)
Roadway width22 ft (6.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,162 (2023)
Projected traffic1,220 by 2043
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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$53,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Frontage Rd-S 205 over Drainage built?

It was built in 1931, making it 94 years old in 2025.

What condition is Frontage Rd-S 205 over Drainage 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 2024.

How much traffic does Frontage Rd-S 205 over Drainage carry?

About 1,162 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is Frontage Rd-S 205 over Drainage?

The structure is 23 ft (7 m) long with a longest span of 22 ft (6.6 m) and a deck 25 ft wide.

Who owns Frontage Rd-S 205 over Drainage?

It is owned by the State Highway Agency.