US Bridges

Sixes Bridge Road over Monocacy River

FairPosted for load

Frederick County, Maryland · 2.5 MI S of Keysville RD · Structure no. 200000F-0503010

Built
1910
115 years old, rebuilt 1995
Condition
Fair
inspected November 2024
Type
Truss - Thru
Steel
Length
240 ft
2 main spans
Daily traffic
207
2024 count
Owner
County
County Highway Agency

About this bridge

Sixes Bridge Road over Monocacy River is a steel truss - thru carrying Sixes Bridge Road over Monocacy River in Frederick County, Maryland. It was built in 1910 and reconstructed in 1995, 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 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 207 vehicles a day, roughly 1% of them trucks, projected to reach 333 by 2046. The structure is 240 ft (73.2 m) long and 16 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesSixes Bridge Road
CrossesMonocacy River
Location2.5 MI S of Keysville RD
RouteCounty Highway 61
CountyFrederick County
StateMaryland
Coordinates39.63021, -77.28839
Functional classRural Minor 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 protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourCountermeasures installed to correct a previously existing problem
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 adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating35.5 US tons
Inventory rating20.9 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans2
Design loadUnknown
Structure length240 ft (73.2 m)
Longest span119 ft (36.3 m)
Deck width16 ft (4.8 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deck11 ft (3.4 m)

Traffic and service

Average daily traffic207 (2024)
Projected traffic333 by 2046
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

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

Frequently asked questions

When was Sixes Bridge Road over Monocacy River built?

It was built in 1910, making it 115 years old in 2025. It was reconstructed in 1995.

What condition is Sixes Bridge 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 November 2024.

How much traffic does Sixes Bridge Road over Monocacy River carry?

About 207 vehicles per day (2024 count), of which roughly 1% are trucks.

How long is Sixes Bridge Road over Monocacy River?

The structure is 240 ft (73.2 m) long with a longest span of 119 ft (36.3 m) and a deck 16 ft wide.

Who owns Sixes Bridge Road over Monocacy River?

It is owned by the County Highway Agency.