US Bridges

Blackburn RD over Round Island CR

Fair

Limestone County, Alabama · SEC15 T3S R5W · Structure no. 005233

Built
1955
70 years old
Condition
Fair
inspected March 2023
Type
Culvert
Concrete
Length
73 ft
5 main spans
Daily traffic
600
2011 count
Owner
County
County Highway Agency

About this bridge

Blackburn RD over Round Island CR is a concrete culvert carrying Blackburn RD over Round Island CR in Limestone County, Alabama. It was built in 1955, so it is 70 years old, older than the Alabama average of 51.1 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 600 vehicles a day, roughly 1% of them trucks, projected to reach 900 by 2031. The structure is 73 ft (22.3 m) long and 23 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesBlackburn RD
CrossesRound Island CR
LocationSEC15 T3S R5W
RouteCounty Highway 43
CountyLimestone County
StateAlabama
Coordinates34.78168, -87.05431
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating56.2 US tons
Inventory rating33.7 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans5
Design loadH 15
Structure length73 ft (22.3 m)
Longest span14 ft (4.3 m)
Deck width23 ft (7.1 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic600 (2011)
Projected traffic900 by 2031
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedNone recorded
Estimated improvement cost$580,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Blackburn RD over Round Island CR built?

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

What condition is Blackburn RD over Round Island CR 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 March 2023.

How much traffic does Blackburn RD over Round Island CR carry?

About 600 vehicles per day (2011 count), of which roughly 1% are trucks.

How long is Blackburn RD over Round Island CR?

The structure is 73 ft (22.3 m) long with a longest span of 14 ft (4.3 m) and a deck 23 ft wide.

Who owns Blackburn RD over Round Island CR?

It is owned by the County Highway Agency.