US Bridges

US 29 over Sligo Creek

Fair

Montgomery County, Maryland · 0.14 M S of Franklin Ave · Structure no. 100000150010010

Built
1936
89 years old, rebuilt 1972
Condition
Fair
inspected March 2024
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
55,302
2009 count
Owner
State
State Highway Agency

About this bridge

US 29 over Sligo Creek is a concrete slab carrying US 29 over Sligo Creek in Montgomery County, Maryland. It was built in 1936 and reconstructed in 1972, so it is 89 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 55,302 vehicles a day, roughly 8% of them trucks, projected to reach 62,380 by 2026. The structure is 23 ft (7 m) long and 101 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesUS 29
CrossesSligo Creek
Location0.14 M S of Franklin Ave
RouteU.S. Route 29
CountyMontgomery County
StateMaryland
Coordinates39.00745, -77.02047
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.5 US tons
Inventory rating29 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length23 ft (7 m)
Longest span20 ft (6.1 m)
Deck width101 ft (30.9 m)
Roadway width88 ft (26.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic55,302 (2009)
Projected traffic62,380 by 2026
Trucks8%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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$154,000
NavigationNo navigation control on waterway

Frequently asked questions

When was US 29 over Sligo Creek built?

It was built in 1936, making it 89 years old in 2025. It was reconstructed in 1972.

What condition is US 29 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 March 2024.

How much traffic does US 29 over Sligo Creek carry?

About 55,302 vehicles per day (2009 count), of which roughly 8% are trucks.

How long is US 29 over Sligo Creek?

The structure is 23 ft (7 m) long with a longest span of 20 ft (6.1 m) and a deck 101 ft wide.

Who owns US 29 over Sligo Creek?

It is owned by the State Highway Agency.