US Bridges

Dam #4 Road over C&o Canal

GoodPosted for load

Washington County, Maryland · 0.9 Miles from Dam #4 on · Structure no. 3100008P0000000

Built
1971
54 years old, rebuilt 2014
Condition
Good
inspected November 2023
Type
Girder and Floorbeam System
Steel
Length
54 ft
1 main span
Daily traffic
212
2007 count
Owner
Federal
National Park Service

About this bridge

Dam #4 Road over C&o Canal is a steel girder and floorbeam system carrying Dam #4 Road over C&o Canal in Washington County, Maryland. It was built in 1971 and reconstructed in 2014, so it is 54 years old, older than the Maryland average of 52.6 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. Its operating status is: posted for load restriction.

It carries about 212 vehicles a day, roughly 2% of them trucks, projected to reach 233 by 2027. The structure is 54 ft (16.4 m) long and 23 ft wide.

Location

Open in Google Maps
CarriesDam #4 Road
CrossesC&o Canal
Location0.9 Miles from Dam #4 on
RouteFederal Lands Road 212
CountyWashington County
StateMaryland
Coordinates39.49978, -77.84344
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.8 US tons
Inventory rating25 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckWood or timber
Main spans1
Design loadH 20
Structure length54 ft (16.4 m)
Longest span52 ft (16 m)
Deck width23 ft (6.9 m)
Roadway width21 ft (6.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic212 (2007)
Projected traffic233 by 2027
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$40,000 (2017 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Dam #4 Road over C&o Canal built?

It was built in 1971, making it 54 years old in 2025. It was reconstructed in 2014.

What condition is Dam #4 Road over C&o Canal in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does Dam #4 Road over C&o Canal carry?

About 212 vehicles per day (2007 count), of which roughly 2% are trucks.

How long is Dam #4 Road over C&o Canal?

The structure is 54 ft (16.4 m) long with a longest span of 52 ft (16 m) and a deck 23 ft wide.

Who owns Dam #4 Road over C&o Canal?

It is owned by the National Park Service.