US Bridges

U.S. Route 17 over Dismal Swamp Canal

PoorPosted for load

Camden County, North Carolina · South Mills · Structure no. 000000000000G14

Built
1934
91 years old
Condition
Poor
inspected September 2024
Type
Movable - Bascule
Steel
Length
130 ft
1 main span
Daily traffic
3,200
2021 count
Owner
Federal
Corps of Engineers (Civil)

About this bridge

U.S. Route 17 over Dismal Swamp Canal is a steel movable - bascule carrying U.S. Route 17 over Dismal Swamp Canal in Camden County, North Carolina. It was built in 1934, so it is 91 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 4 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. Its operating status is: posted for load restriction.

It carries about 3,200 vehicles a day, roughly 5% of them trucks, projected to reach 3,600 by 2042. The structure is 130 ft (39.5 m) long and 20 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesU.S. Route 17
CrossesDismal Swamp Canal
LocationSouth Mills
RouteU.S. Route 17
Coordinates36.44591, -76.32719
Functional classRural Local

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating44.6 US tons
Inventory rating31.5 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckOpen grating
Main spans1 (+2 approach)
Design loadH 15
Structure length130 ft (39.5 m)
Longest span64 ft (19.5 m)
Deck width20 ft (6.1 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,200 (2021)
Projected traffic3,600 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCorps of Engineers (Civil)
Maintained byCorps of Engineers (Civil)
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$31 million (2020 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was U.S. Route 17 over Dismal Swamp Canal built?

It was built in 1934, making it 91 years old in 2025.

What condition is U.S. Route 17 over Dismal Swamp Canal 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 September 2024.

How much traffic does U.S. Route 17 over Dismal Swamp Canal carry?

About 3,200 vehicles per day (2021 count), of which roughly 5% are trucks.

How long is U.S. Route 17 over Dismal Swamp Canal?

The structure is 130 ft (39.5 m) long with a longest span of 64 ft (19.5 m) and a deck 20 ft wide.

Who owns U.S. Route 17 over Dismal Swamp Canal?

It is owned by the Corps of Engineers (Civil).