US Bridges

Jones Mill Road over Rock Creek

Fair

Montgomery County, Maryland · 0.1 MI S Forsythe Avenue · Structure no. 200000M-0075010

Built
1969
56 years old, rebuilt 2000
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
201 ft
4 main spans
Daily traffic
7,194
2023 count
Owner
County
County Highway Agency

About this bridge

Jones Mill Road over Rock Creek is a steel stringer/multi-beam or girder carrying Jones Mill Road over Rock Creek in Montgomery County, Maryland. It was built in 1969 and reconstructed in 2000, so it is 56 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 7,194 vehicles a day, roughly 2% of them trucks, projected to reach 8,070 by 2045. The structure is 201 ft (61.3 m) long and 36 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesJones Mill Road
CrossesRock Creek
Location0.1 MI S Forsythe Avenue
RouteCounty Highway 4460
CountyMontgomery County
StateMaryland
Coordinates39.01099, -77.06306
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating70 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length201 ft (61.3 m)
Longest span51 ft (15.5 m)
Deck width36 ft (11.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,194 (2023)
Projected traffic8,070 by 2045
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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 statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$11,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Jones Mill Road over Rock Creek built?

It was built in 1969, making it 56 years old in 2025. It was reconstructed in 2000.

What condition is Jones Mill Road over Rock Creek 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 June 2024.

How much traffic does Jones Mill Road over Rock Creek carry?

About 7,194 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is Jones Mill Road over Rock Creek?

The structure is 201 ft (61.3 m) long with a longest span of 51 ft (15.5 m) and a deck 36 ft wide.

Who owns Jones Mill Road over Rock Creek?

It is owned by the County Highway Agency.