US Bridges

Md 355 over Monocacy River

Fair

Frederick County, Maryland · 2.29 Miles South of Md 85 · Structure no. 100000100085010

Built
1930
95 years old, rebuilt 1980
Condition
Fair
inspected June 2024
Type
Truss - Thru
Steel
Length
315 ft
2 main spans
Daily traffic
12,583
2022 count
Owner
State
State Highway Agency

About this bridge

Md 355 over Monocacy River is a steel truss - thru carrying Md 355 over Monocacy River in Frederick County, Maryland. It was built in 1930 and reconstructed in 1980, so it is 95 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 12,583 vehicles a day, roughly 8% of them trucks, projected to reach 16,638 by 2044. The structure is 315 ft (96 m) long and 25 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesMd 355
CrossesMonocacy River
Location2.29 Miles South of Md 85
RouteState Highway 355
CountyFrederick County
StateMaryland
Coordinates39.36954, -77.39054
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 12 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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.5 US tons
Inventory rating26.5 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadH 20
Structure length315 ft (96 m)
Longest span154 ft (46.9 m)
Deck width25 ft (7.7 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic12,583 (2022)
Projected traffic16,638 by 2044
Trucks8%
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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$518,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Md 355 over Monocacy River built?

It was built in 1930, making it 95 years old in 2025. It was reconstructed in 1980.

What condition is Md 355 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 June 2024.

How much traffic does Md 355 over Monocacy River carry?

About 12,583 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is Md 355 over Monocacy River?

The structure is 315 ft (96 m) long with a longest span of 154 ft (46.9 m) and a deck 25 ft wide.

Who owns Md 355 over Monocacy River?

It is owned by the State Highway Agency.