US Bridges

US158 over I40 Bus US158 & US421

Fair

Forsyth County, North Carolina · 0.3 Mi. S. Jct. SR1001 · Structure no. 000000000670125

Built
1956
69 years old, rebuilt 1995
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
178 ft
4 main spans
Daily traffic
17,500
2021 count
Owner
State
State Highway Agency

About this bridge

US158 over I40 Bus US158 & US421 is a steel stringer/multi-beam or girder carrying US158 over I40 Bus US158 & US421 in Forsyth County, North Carolina. It was built in 1956 and reconstructed in 1995, so it is 69 years old, older than the North Carolina average of 38.7 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.

It carries about 17,500 vehicles a day, roughly 6% of them trucks, projected to reach 35,000 by 2040. The structure is 178 ft (54.2 m) long and 74 ft wide.

Location

Open in Google Maps
CarriesUS158
CrossesI40 Bus US158 & US421
Location0.3 Mi. S. Jct. SR1001
RouteU.S. Route 158
CountyForsyth County
StateNorth Carolina
Coordinates36.09392, -80.27908
Functional classUrban Minor Arterial

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64.9 US tons
Inventory rating38.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length178 ft (54.2 m)
Longest span57 ft (17.3 m)
Deck width74 ft (22.7 m)
Roadway width64 ft (19.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,500 (2021)
Projected traffic35,000 by 2040
Trucks6%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US158 over I40 Bus US158 & US421 built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 1995.

What condition is US158 over I40 Bus US158 & US421 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 November 2023.

How much traffic does US158 over I40 Bus US158 & US421 carry?

About 17,500 vehicles per day (2021 count), of which roughly 6% are trucks.

How long is US158 over I40 Bus US158 & US421?

The structure is 178 ft (54.2 m) long with a longest span of 57 ft (17.3 m) and a deck 74 ft wide.

Who owns US158 over I40 Bus US158 & US421?

It is owned by the State Highway Agency.