US Bridges

Quinn Road over Is 70

Fair

Frederick County, Maryland · 0.39 MI N or CO 377 · Structure no. 100000100187010

Built
1985
40 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
246 ft
2 main spans
Daily traffic
792
1994 count
Owner
State
State Highway Agency

About this bridge

Quinn Road over Is 70 is a steel continuous stringer/multi-beam or girder carrying Quinn Road over Is 70 in Frederick County, Maryland. It was built in 1985, so it is 40 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 792 vehicles a day, roughly 5% of them trucks, projected to reach 348 by 2012. The structure is 246 ft (75 m) long and 47 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesQuinn Road
CrossesIs 70
Location0.39 MI N or CO 377
RouteCounty Highway 852
CountyFrederick County
StateMaryland
Coordinates39.40043, -77.33564
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70.4 US tons
Inventory rating42.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length246 ft (75 m)
Longest span121 ft (36.9 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic792 (1994)
Projected traffic348 by 2012
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Quinn Road over Is 70 built?

It was built in 1985, making it 40 years old in 2025.

What condition is Quinn Road over Is 70 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 August 2024.

How much traffic does Quinn Road over Is 70 carry?

About 792 vehicles per day (1994 count), of which roughly 5% are trucks.

How long is Quinn Road over Is 70?

The structure is 246 ft (75 m) long with a longest span of 121 ft (36.9 m) and a deck 47 ft wide.

Who owns Quinn Road over Is 70?

It is owned by the State Highway Agency.