US Bridges

Dennis Avenue over Sligo Creek

Fair

Montgomery County, Maryland · 0.7 Miles East of Md 97 · Structure no. 200000M-0156010

Built
1999
26 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
73 ft
1 main span
Daily traffic
10,971
2021 count
Owner
County
County Highway Agency

About this bridge

Dennis Avenue over Sligo Creek is a prestressed concrete box beam or girders - multiple carrying Dennis Avenue over Sligo Creek in Montgomery County, Maryland. It was built in 1999, so it is 26 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 6 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 10,971 vehicles a day, roughly 5% of them trucks, projected to reach 12,948 by 2041. The structure is 73 ft (22.1 m) long and 49 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesDennis Avenue
CrossesSligo Creek
Location0.7 Miles East of Md 97
RouteCounty Highway 793
CountyMontgomery County
StateMaryland
Coordinates39.02414, -77.03044
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
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 rating110.1 US tons
Inventory rating74 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length73 ft (22.1 m)
Longest span68 ft (20.7 m)
Deck width49 ft (14.8 m)
Roadway width36 ft (11.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,971 (2021)
Projected traffic12,948 by 2041
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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 Dennis Avenue over Sligo Creek built?

It was built in 1999, making it 26 years old in 2025.

What condition is Dennis Avenue over Sligo 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 October 2023.

How much traffic does Dennis Avenue over Sligo Creek carry?

About 10,971 vehicles per day (2021 count), of which roughly 5% are trucks.

How long is Dennis Avenue over Sligo Creek?

The structure is 73 ft (22.1 m) long with a longest span of 68 ft (20.7 m) and a deck 49 ft wide.

Who owns Dennis Avenue over Sligo Creek?

It is owned by the County Highway Agency.