US Bridges

Carroll Mill Road over Middle Patuxent River

Fair

Howard County, Maryland · 0.4 MI W of Folly Quarter · Structure no. 200000HO0022020

Built
1975
50 years old
Condition
Fair
inspected April 2024
Type
Culvert
Concrete
Length
41 ft
Daily traffic
2,736
2024 count
Owner
County
County Highway Agency

About this bridge

Carroll Mill Road over Middle Patuxent River is a concrete culvert carrying Carroll Mill Road over Middle Patuxent River in Howard County, Maryland. It was built in 1975, so it is 50 years old, younger 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 2,736 vehicles a day, roughly 4% of them trucks, projected to reach 4,942 by 2044. The structure is 41 ft (12.5 m) long and 38 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesCarroll Mill Road
CrossesMiddle Patuxent River
Location0.4 MI W of Folly Quarter
RouteCounty Highway 74
CountyHoward County
StateMaryland
Coordinates39.26633, -76.92874
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 12 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64.5 US tons
Inventory rating38.5 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans0
Design loadUnknown
Structure length41 ft (12.5 m)
Longest span20 ft (6.1 m)
Deck width38 ft (11.6 m)
Roadway width36 ft (11 m)
Vertical clearance over deck17 ft (5.2 m)

Traffic and service

Average daily traffic2,736 (2024)
Projected traffic4,942 by 2044
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

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

Frequently asked questions

When was Carroll Mill Road over Middle Patuxent River built?

It was built in 1975, making it 50 years old in 2025.

What condition is Carroll Mill Road over Middle Patuxent 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 Carroll Mill Road over Middle Patuxent River carry?

About 2,736 vehicles per day (2024 count), of which roughly 4% are trucks.

How long is Carroll Mill Road over Middle Patuxent River?

The structure is 41 ft (12.5 m) long with a longest span of 20 ft (6.1 m) and a deck 38 ft wide.

Who owns Carroll Mill Road over Middle Patuxent River?

It is owned by the County Highway Agency.