US Bridges

Md 4 over Patuxent River & Town CR

Fair

Calvert County, Maryland · On ST Marys CO Line · Structure no. 100000040019010

Built
1977
48 years old
Condition
Fair
inspected November 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
7,207 ft
9 main spans
Daily traffic
28,338
2023 count
Owner
State
State Highway Agency

About this bridge

Md 4 over Patuxent River & Town CR is a steel continuous girder and floorbeam system carrying Md 4 over Patuxent River & Town CR in Calvert County, Maryland. It was built in 1977, so it is 48 years old, younger 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 28,338 vehicles a day, roughly 8% of them trucks, projected to reach 30,377 by 2043. The structure is 7,207 ft (2,196.7 m) long and 31 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

Open in Google Maps
CarriesMd 4
CrossesPatuxent River & Town CR
LocationOn ST Marys CO Line
RouteState Highway 4
CountyCalvert County
StateMaryland
Coordinates38.31861, -76.48491
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
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 protection8 Very GoodNo problems noted.
Last inspectionNovember 2023
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.5 US tons
Inventory rating22.5 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans9 (+50 approach)
Design loadHS 20
Structure length7,207 ft (2,196.7 m)
Longest span451 ft (137.5 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,338 (2023)
Projected traffic30,377 by 2043
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed49.7 mi (80 km)
TollOn a free road
National Highway SystemYes

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$14.8 million
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Md 4 over Patuxent River & Town CR built?

It was built in 1977, making it 48 years old in 2025.

What condition is Md 4 over Patuxent River & Town CR 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 Md 4 over Patuxent River & Town CR carry?

About 28,338 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is Md 4 over Patuxent River & Town CR?

The structure is 7,207 ft (2,196.7 m) long with a longest span of 451 ft (137.5 m) and a deck 31 ft wide.

Who owns Md 4 over Patuxent River & Town CR?

It is owned by the State Highway Agency.