US Bridges

Md 28 over Monocacy River

Fair

Frederick County, Maryland · 0.98 MI W of Mont CO · Structure no. 100000100029010

Built
1931
94 years old, rebuilt 2021
Condition
Fair
inspected May 2023
Type
Truss - Thru
Steel
Length
449 ft
3 main spans
Daily traffic
9,175
2022 count
Owner
State
State Highway Agency

About this bridge

Md 28 over Monocacy River is a steel truss - thru carrying Md 28 over Monocacy River in Frederick County, Maryland. It was built in 1931 and reconstructed in 2021, so it is 94 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 9,175 vehicles a day, roughly 4% of them trucks, projected to reach 10,000 by 2042. The structure is 449 ft (137 m) long and 28 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesMd 28
CrossesMonocacy River
Location0.98 MI W of Mont CO
RouteState Highway 28
CountyFrederick County
StateMaryland
Coordinates39.24381, -77.43958
Functional classRural 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
Deck7 GoodSome minor problems.
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.5 US tons
Inventory rating34.5 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length449 ft (137 m)
Longest span145 ft (44.2 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.6 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic9,175 (2022)
Projected traffic10,000 by 2042
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$9.5 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Md 28 over Monocacy River built?

It was built in 1931, making it 94 years old in 2025. It was reconstructed in 2021.

What condition is Md 28 over Monocacy 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 May 2023.

How much traffic does Md 28 over Monocacy River carry?

About 9,175 vehicles per day (2022 count), of which roughly 4% are trucks.

How long is Md 28 over Monocacy River?

The structure is 449 ft (137 m) long with a longest span of 145 ft (44.2 m) and a deck 28 ft wide.

Who owns Md 28 over Monocacy River?

It is owned by the State Highway Agency.