US Bridges

I840 over I840/ S Garrison Branc

Fair

Williamson County, Tennessee · 4 MI S SR46 · Structure no. 94SR8400106

Built
2012
13 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
841 ft
7 main spans
Daily traffic
22,556
2021 count
Owner
State
State Highway Agency

About this bridge

I840 over I840/ S Garrison Branc is a prestressed concrete continuous stringer/multi-beam or girder carrying I840 over I840/ S Garrison Branc in Williamson County, Tennessee. It was built in 2012, so it is 13 years old, younger than the Tennessee average of 47.4 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 22,556 vehicles a day, roughly 7% of them trucks, projected to reach 30,736 by 2042. The structure is 841 ft (256.2 m) long and 43 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesI840
CrossesI840/ S Garrison Branc
Location4 MI S SR46
RouteInterstate 840
CountyWilliamson County
StateTennessee
Coordinates35.85209, -87.07117
Functional classRural Principal Arterial - Interstate

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating15.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, precast panels
Main spans7
Design loadHL 93
Structure length841 ft (256.2 m)
Longest span145 ft (44.2 m)
Deck width43 ft (13.2 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22,556 (2021)
Projected traffic30,736 by 2042
Trucks7%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$8.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I840 over I840/ S Garrison Branc built?

It was built in 2012, making it 13 years old in 2025.

What condition is I840 over I840/ S Garrison Branc 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 December 2024.

How much traffic does I840 over I840/ S Garrison Branc carry?

About 22,556 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is I840 over I840/ S Garrison Branc?

The structure is 841 ft (256.2 m) long with a longest span of 145 ft (44.2 m) and a deck 43 ft wide.

Who owns I840 over I840/ S Garrison Branc?

It is owned by the State Highway Agency.