US Bridges

Inwood Avenue over Sligo Creek Tributary

Good

Montgomery County, Maryland · At Folk Street · Structure no. 200000M-0139010

Built
1956
69 years old, rebuilt 2006
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
42 ft
1 main span
Daily traffic
2,972
2024 count
Owner
County
County Highway Agency

About this bridge

Inwood Avenue over Sligo Creek Tributary is a steel stringer/multi-beam or girder carrying Inwood Avenue over Sligo Creek Tributary in Montgomery County, Maryland. It was built in 1956 and reconstructed in 2006, so it is 69 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.

It carries about 2,972 vehicles a day, roughly 3% of them trucks, projected to reach 3,506 by 2044. The structure is 42 ft (12.8 m) long and 38 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesInwood Avenue
CrossesSligo Creek Tributary
LocationAt Folk Street
RouteCounty Highway 1270
Coordinates39.02355, -77.03531
Functional classUrban Local

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 protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating110.1 US tons
Inventory rating60 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length42 ft (12.8 m)
Longest span41 ft (12.5 m)
Deck width38 ft (11.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,972 (2024)
Projected traffic3,506 by 2044
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 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 Inwood Avenue over Sligo Creek Tributary built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 2006.

What condition is Inwood Avenue over Sligo Creek Tributary 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 October 2024.

How much traffic does Inwood Avenue over Sligo Creek Tributary carry?

About 2,972 vehicles per day (2024 count), of which roughly 3% are trucks.

How long is Inwood Avenue over Sligo Creek Tributary?

The structure is 42 ft (12.8 m) long with a longest span of 41 ft (12.5 m) and a deck 38 ft wide.

Who owns Inwood Avenue over Sligo Creek Tributary?

It is owned by the County Highway Agency.