US Bridges

Md 231 over Patuxent River

Fair

Calvert County, Maryland · On Charles CO Line · Structure no. 100000040008010

Built
1952
73 years old
Condition
Fair
inspected February 2024
Type
Movable - Swing
Steel
Length
3,348 ft
2 main spans
Daily traffic
11,784
2021 count
Owner
State
State Highway Agency

About this bridge

Md 231 over Patuxent River is a steel movable - swing carrying Md 231 over Patuxent River in Calvert County, Maryland. It was built in 1952, so it is 73 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 11,784 vehicles a day, roughly 7% of them trucks, projected to reach 11,784 by 2042. The structure is 3,348 ft (1,020.5 m) long and 27 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

Open in Google Maps
CarriesMd 231
CrossesPatuxent River
LocationOn Charles CO Line
RouteState Highway 231
CountyCalvert County
StateMaryland
Coordinates38.51481, -76.67433
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating42.4 US tons
Inventory rating25.5 US tons

Structure

Structure typeMovable - Swing
MaterialSteel
DeckConcrete, cast-in-place
Main spans2 (+56 approach)
Design loadH 20
Structure length3,348 ft (1,020.5 m)
Longest span78 ft (23.8 m)
Deck width27 ft (8.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deck16 ft (4.9 m)

Traffic and service

Average daily traffic11,784 (2021)
Projected traffic11,784 by 2042
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed31.7 mi (51 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$6 million
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Md 231 over Patuxent River built?

It was built in 1952, making it 73 years old in 2025.

What condition is Md 231 over Patuxent River 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 February 2024.

How much traffic does Md 231 over Patuxent River carry?

About 11,784 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is Md 231 over Patuxent River?

The structure is 3,348 ft (1,020.5 m) long with a longest span of 78 ft (23.8 m) and a deck 27 ft wide.

Who owns Md 231 over Patuxent River?

It is owned by the State Highway Agency.