US Bridges

I840 over I 840-LL / CSX RR

Good

Williamson County, Tennessee · 3.0 MI W JCT.SR106&I840 · Structure no. 94SR8400044

Built
2001
24 years old
Condition
Good
inspected February 2025
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
176 ft
3 main spans
Daily traffic
21,372
2021 count
Owner
State
State Highway Agency

About this bridge

I840 over I 840-LL / CSX RR is a prestressed concrete continuous stringer/multi-beam or girder carrying I840 over I 840-LL / CSX RR in Williamson County, Tennessee. It was built in 2001, so it is 24 years old, younger than the Tennessee average of 47.4 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 21,372 vehicles a day, roughly 7% of them trucks, projected to reach 37,968 by 2041. The structure is 176 ft (53.6 m) long and 44 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

CarriesI840
CrossesI 840-LL / CSX RR
Location3.0 MI W JCT.SR106&I840
RouteInterstate 840
Coordinates35.82281, -86.89829
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.4 US tons
Inventory rating35.7 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length176 ft (53.6 m)
Longest span64 ft (19.5 m)
Deck width44 ft (13.4 m)
Roadway width42 ft (12.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,372 (2021)
Projected traffic37,968 by 2041
Trucks7%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I840 over I 840-LL / CSX RR built?

It was built in 2001, making it 24 years old in 2025.

What condition is I840 over I 840-LL / CSX RR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in February 2025.

How much traffic does I840 over I 840-LL / CSX RR carry?

About 21,372 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is I840 over I 840-LL / CSX RR?

The structure is 176 ft (53.6 m) long with a longest span of 64 ft (19.5 m) and a deck 44 ft wide.

Who owns I840 over I 840-LL / CSX RR?

It is owned by the State Highway Agency.