US Bridges

Bullfrog Road over Monocacy River

FairPosted for load

Frederick County, Maryland · 0.6 MI S of Bollinger Scl · Structure no. 200000F-0506010

Built
1908
117 years old, rebuilt 1995
Condition
Fair
inspected April 2024
Type
Truss - Thru
Aluminum, Wrought Iron, or Cast Iron
Length
183 ft
1 main span
Daily traffic
324
2022 count
Owner
County
County Highway Agency

About this bridge

Bullfrog Road over Monocacy River is a aluminum, wrought iron, or cast iron truss - thru carrying Bullfrog Road over Monocacy River in Frederick County, Maryland. It was built in 1908 and reconstructed in 1995, so it is 117 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. Its operating status is: posted for load restriction.

It carries about 324 vehicles a day, roughly 1% of them trucks, projected to reach 482 by 2042. The structure is 183 ft (55.8 m) long and 16 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesBullfrog Road
CrossesMonocacy River
Location0.6 MI S of Bollinger Scl
RouteCounty Highway 49
CountyFrederick County
StateMaryland
Coordinates39.69531, -77.24009
Functional classRural Local

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.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 12 months
Operating statusPosted for load 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating48.5 US tons
Inventory rating29 US tons

Structure

Structure typeTruss - Thru
MaterialAluminum, Wrought Iron, or Cast Iron
DeckWood or timber
Main spans1
Design loadUnknown
Structure length183 ft (55.8 m)
Longest span183 ft (55.8 m)
Deck width16 ft (5 m)
Roadway width13 ft (4 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic324 (2022)
Projected traffic482 by 2042
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Bullfrog Road over Monocacy River built?

It was built in 1908, making it 117 years old in 2025. It was reconstructed in 1995.

What condition is Bullfrog Road 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 April 2024.

How much traffic does Bullfrog Road over Monocacy River carry?

About 324 vehicles per day (2022 count), of which roughly 1% are trucks.

How long is Bullfrog Road over Monocacy River?

The structure is 183 ft (55.8 m) long with a longest span of 183 ft (55.8 m) and a deck 16 ft wide.

Who owns Bullfrog Road over Monocacy River?

It is owned by the County Highway Agency.