US Bridges

US 340 over Potomac River CSX Trans

Fair

Washington County, Maryland · On Virginia State Line · Structure no. 100000210041010

Built
1946
79 years old, rebuilt 1978
Condition
Fair
inspected December 2023
Type
Truss - Deck
Steel Continuous
Length
2,251 ft
12 main spans
Daily traffic
20,830
2022 count
Owner
State
State Highway Agency

About this bridge

US 340 over Potomac River CSX Trans is a steel continuous truss - deck carrying US 340 over Potomac River CSX Trans in Washington County, Maryland. It was built in 1946 and reconstructed in 1978, so it is 79 years old, older than the Maryland average of 52.6 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 20,830 vehicles a day, roughly 9% of them trucks, projected to reach 23,011 by 2042. The structure is 2,251 ft (686.1 m) long and 37 ft wide. If it were closed, the detour would be 19.3 mi (31 km).

CarriesUS 340
CrossesPotomac River CSX Trans
LocationOn Virginia State Line
RouteU.S. Route 340
Coordinates39.32109, -77.70991
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 18 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating36 US tons
Inventory rating16 US tons

Structure

Structure typeTruss - Deck
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans12 (+2 approach)
Design loadH 20
Structure length2,251 ft (686.1 m)
Longest span190 ft (57.9 m)
Deck width37 ft (11.2 m)
Roadway width25 ft (7.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20,830 (2022)
Projected traffic23,011 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway, waterway and railroad
Detour if closed19.3 mi (31 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$5.5 million
NavigationNo navigation control on waterway

Frequently asked questions

When was US 340 over Potomac River CSX Trans built?

It was built in 1946, making it 79 years old in 2025. It was reconstructed in 1978.

What condition is US 340 over Potomac River CSX Trans 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 2023.

How much traffic does US 340 over Potomac River CSX Trans carry?

About 20,830 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is US 340 over Potomac River CSX Trans?

The structure is 2,251 ft (686.1 m) long with a longest span of 190 ft (57.9 m) and a deck 37 ft wide.

Who owns US 340 over Potomac River CSX Trans?

It is owned by the State Highway Agency.