US Bridges

Md 320 over Northwest Branch

Fair

Prince George's County, Maryland · 0.05 Mile South of Md 650 · Structure no. 100000160065010

Built
1910
115 years old, rebuilt 1955
Condition
Fair
inspected November 2024
Type
Arch - Deck
Concrete
Length
60 ft
1 main span
Daily traffic
21,112
2009 count
Owner
State
State Highway Agency

About this bridge

Md 320 over Northwest Branch is a concrete arch - deck carrying Md 320 over Northwest Branch in Prince George's County, Maryland. It was built in 1910 and reconstructed in 1955, so it is 115 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 6 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 21,112 vehicles a day, roughly 8% of them trucks, projected to reach 26,660 by 2026. The structure is 60 ft (18.3 m) long and 70 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesMd 320
CrossesNorthwest Branch
Location0.05 Mile South of Md 650
RouteState Highway 320
CountyPrince George's County
StateMaryland
Coordinates39.00158, -76.98321
Functional classUrban Minor Arterial

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating42.4 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length60 ft (18.3 m)
Longest span56 ft (17.1 m)
Deck width70 ft (21.3 m)
Roadway width58 ft (17.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,112 (2009)
Projected traffic26,660 by 2026
Trucks8%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Md 320 over Northwest Branch built?

It was built in 1910, making it 115 years old in 2025. It was reconstructed in 1955.

What condition is Md 320 over Northwest Branch 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 2024.

How much traffic does Md 320 over Northwest Branch carry?

About 21,112 vehicles per day (2009 count), of which roughly 8% are trucks.

How long is Md 320 over Northwest Branch?

The structure is 60 ft (18.3 m) long with a longest span of 56 ft (17.1 m) and a deck 70 ft wide.

Who owns Md 320 over Northwest Branch?

It is owned by the State Highway Agency.