US Bridges

Town Line Road over Big Brook

Fair

Jefferson County, New York · 2 MI NW of Diamond · Structure no. 000000003363400

Built
1941
84 years old, rebuilt 1991
Condition
Fair
inspected October 2024
Type
Slab
Wood or Timber
Length
29 ft
1 main span
Daily traffic
27
2019 count
Owner
County
County Highway Agency

About this bridge

Town Line Road over Big Brook is a wood or timber slab carrying Town Line Road over Big Brook in Jefferson County, New York. It was built in 1941 and reconstructed in 1991, so it is 84 years old, older than the New York average of 53 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 27 vehicles a day, roughly 17% of them trucks, projected to reach 38 by 2039. The structure is 29 ft (8.8 m) long and 15 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesTown Line Road
CrossesBig Brook
Location2 MI NW of Diamond
CountyJefferson County
StateNew York
Coordinates43.73303, -75.90761
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure8 Very GoodNo problems noted.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating66 US tons
Inventory rating47 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckNot applicable
Main spans1
Design loadHS 20
Structure length29 ft (8.8 m)
Longest span28 ft (8.5 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27 (2019)
Projected traffic38 by 2039
Trucks17%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$184,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Town Line Road over Big Brook built?

It was built in 1941, making it 84 years old in 2025. It was reconstructed in 1991.

What condition is Town Line Road over Big Brook 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 October 2024.

How much traffic does Town Line Road over Big Brook carry?

About 27 vehicles per day (2019 count), of which roughly 17% are trucks.

How long is Town Line Road over Big Brook?

The structure is 29 ft (8.8 m) long with a longest span of 28 ft (8.5 m) and a deck 15 ft wide.

Who owns Town Line Road over Big Brook?

It is owned by the County Highway Agency.