US Bridges

Tn Route 20 over Natchez Trace Parkway

Good

Lewis County, Tennessee · 5.6 Miles to U.S. Route 4 · Structure no. 5570188P0000000

Built
1960
65 years old
Condition
Good
inspected February 2025
Type
Arch - Deck
Concrete
Length
74 ft
1 main span
Daily traffic
485
2019 count
Owner
Federal
National Park Service

About this bridge

Tn Route 20 over Natchez Trace Parkway is a concrete arch - deck carrying Tn Route 20 over Natchez Trace Parkway in Lewis County, Tennessee. It was built in 1960, so it is 65 years old, older 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 485 vehicles a day, roughly 4% of them trucks, projected to reach 500 by 2039. The structure is 74 ft (22.7 m) long and 34 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

Open in Google Maps
CarriesTn Route 20
CrossesNatchez Trace Parkway
Location5.6 Miles to U.S. Route 4
RouteFederal Lands Road 1
CountyLewis County
StateTennessee
Coordinates35.50358, -87.45844
Functional classRural Minor Collector

Condition and inspection

Good

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

ComponentRatingMeaning
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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating34.9 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadH 15
Structure length74 ft (22.7 m)
Longest span74 ft (22.7 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic485 (2019)
Projected traffic500 by 2039
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed49.7 mi (80 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$18,000 (2021 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Tn Route 20 over Natchez Trace Parkway built?

It was built in 1960, making it 65 years old in 2025.

What condition is Tn Route 20 over Natchez Trace Parkway 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 Tn Route 20 over Natchez Trace Parkway carry?

About 485 vehicles per day (2019 count), of which roughly 4% are trucks.

How long is Tn Route 20 over Natchez Trace Parkway?

The structure is 74 ft (22.7 m) long with a longest span of 74 ft (22.7 m) and a deck 34 ft wide.

Who owns Tn Route 20 over Natchez Trace Parkway?

It is owned by the National Park Service.