US Bridges

Bowie Mill Road over Rock Creek North Branch

Fair

Montgomery County, Maryland · 1.8 Miles NE of Md 115 · Structure no. 200000M-0069010

Built
1959
66 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
42 ft
1 main span
Daily traffic
10,400
2023 count
Owner
County
County Highway Agency

About this bridge

Bowie Mill Road over Rock Creek North Branch is a steel stringer/multi-beam or girder carrying Bowie Mill Road over Rock Creek North Branch in Montgomery County, Maryland. It was built in 1959, so it is 66 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 10,400 vehicles a day, roughly 5% of them trucks, projected to reach 14,430 by 2045. The structure is 42 ft (12.8 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesBowie Mill Road
CrossesRock Creek North Branch
Location1.8 Miles NE of Md 115
RouteCounty Highway 135
CountyMontgomery County
StateMaryland
Coordinates39.15077, -77.10355
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating110.1 US tons
Inventory rating68 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckSteel plate
Main spans1
Design loadH 20
Structure length42 ft (12.8 m)
Longest span39 ft (11.9 m)
Deck width33 ft (10.1 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,400 (2023)
Projected traffic14,430 by 2045
Trucks5%
Lanes on structure2
Traffic directionTwo-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 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 Bowie Mill Road over Rock Creek North Branch built?

It was built in 1959, making it 66 years old in 2025.

What condition is Bowie Mill Road over Rock Creek North Branch 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 March 2023.

How much traffic does Bowie Mill Road over Rock Creek North Branch carry?

About 10,400 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Bowie Mill Road over Rock Creek North Branch?

The structure is 42 ft (12.8 m) long with a longest span of 39 ft (11.9 m) and a deck 33 ft wide.

Who owns Bowie Mill Road over Rock Creek North Branch?

It is owned by the County Highway Agency.