US Bridges

US21BUS over I-77

Poor

Yadkin County, North Carolina · .15 MI.N.JCT.SR1350 · Structure no. 000000001970029

Built
1964
61 years old
Condition
Poor
inspected January 2025
Type
Stringer/Multi-beam or Girder
Steel
Length
390 ft
6 main spans
Daily traffic
3,100
2021 count
Owner
State
State Highway Agency

About this bridge

US21BUS over I-77 is a steel stringer/multi-beam or girder carrying US21BUS over I-77 in Yadkin County, North Carolina. It was built in 1964, so it is 61 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 poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 3,100 vehicles a day, roughly 7% of them trucks, projected to reach 6,200 by 2040. The structure is 390 ft (118.8 m) long and 33 ft wide.

Location

Open in Google Maps
CarriesUS21BUS
CrossesI-77
Location.15 MI.N.JCT.SR1350
RouteU.S. Route 21
CountyYadkin County
StateNorth Carolina
Coordinates36.19748, -80.8113
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Last inspectionJanuary 2025
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20 + Mod
Structure length390 ft (118.8 m)
Longest span103 ft (31.3 m)
Deck width33 ft (10.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,100 (2021)
Projected traffic6,200 by 2040
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was US21BUS over I-77 built?

It was built in 1964, making it 61 years old in 2025.

What condition is US21BUS over I-77 in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in January 2025.

How much traffic does US21BUS over I-77 carry?

About 3,100 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is US21BUS over I-77?

The structure is 390 ft (118.8 m) long with a longest span of 103 ft (31.3 m) and a deck 33 ft wide.

Who owns US21BUS over I-77?

It is owned by the State Highway Agency.