US Bridges

KY-687 over Big Dog Branch

FairPosted for load

Clay County, Kentucky · 9.9 MI West of JCT US 421 · Structure no. 026B00038N

Built
1955
70 years old
Condition
Fair
inspected August 2024
Type
Slab
Concrete
Length
25 ft
1 main span
Daily traffic
133
2023 count
Owner
State
State Highway Agency

About this bridge

KY-687 over Big Dog Branch is a concrete slab carrying KY-687 over Big Dog Branch in Clay County, Kentucky. It was built in 1955, so it is 70 years old, older than the Kentucky average of 46.6 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. Its operating status is: posted for load restriction.

It carries about 133 vehicles a day, projected to reach 133 by 2043. The structure is 25 ft (7.6 m) long and 25 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesKY-687
CrossesBig Dog Branch
Location9.9 MI West of JCT US 421
RouteState Highway 687
CountyClay County
StateKentucky
Coordinates37.14667, -83.88917
Functional classRural Minor 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating29.9 US tons
Inventory rating17.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length25 ft (7.6 m)
Longest span22 ft (6.7 m)
Deck width25 ft (7.6 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic133 (2023)
Projected traffic133 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was KY-687 over Big Dog Branch built?

It was built in 1955, making it 70 years old in 2025.

What condition is KY-687 over Big Dog Branch 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 August 2024.

How much traffic does KY-687 over Big Dog Branch carry?

About 133 vehicles per day (2023 count).

How long is KY-687 over Big Dog Branch?

The structure is 25 ft (7.6 m) long with a longest span of 22 ft (6.7 m) and a deck 25 ft wide.

Who owns KY-687 over Big Dog Branch?

It is owned by the State Highway Agency.