US Bridges

Md 257 over Mill Run

Fair

Charles County, Maryland · 0.053 M N of Mill Run RD · Structure no. 100000080001010

Built
1900
125 years old, rebuilt 1949
Condition
Fair
inspected June 2024
Type
Culvert
Concrete
Length
23 ft
Daily traffic
3,990
2009 count
Owner
State
State Highway Agency

About this bridge

Md 257 over Mill Run is a concrete culvert carrying Md 257 over Mill Run in Charles County, Maryland. It was built in 1900 and reconstructed in 1949, so it is 125 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 3,990 vehicles a day, roughly 8% of them trucks, projected to reach 4,600 by 2026. The structure is 23 ft (7 m) long and 38 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesMd 257
CrossesMill Run
Location0.053 M N of Mill Run RD
RouteState Highway 257
CountyCharles County
StateMaryland
Coordinates38.34491, -76.92415
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 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 rating50 US tons
Inventory rating30 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans0
Design loadH 20
Structure length23 ft (7 m)
Longest span10 ft (3 m)
Deck width38 ft (11.7 m)
Roadway width37 ft (11.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,990 (2009)
Projected traffic4,600 by 2026
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 257 over Mill Run built?

It was built in 1900, making it 125 years old in 2025. It was reconstructed in 1949.

What condition is Md 257 over Mill Run 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 June 2024.

How much traffic does Md 257 over Mill Run carry?

About 3,990 vehicles per day (2009 count), of which roughly 8% are trucks.

How long is Md 257 over Mill Run?

The structure is 23 ft (7 m) long with a longest span of 10 ft (3 m) and a deck 38 ft wide.

Who owns Md 257 over Mill Run?

It is owned by the State Highway Agency.