US Bridges

Is 70 over Grindstone Run

Fair

Frederick County, Maryland · 0.3 Mile West of Md 17 · Structure no. 100000100135010

Built
1968
57 years old
Condition
Fair
inspected June 2024
Type
Arch - Deck
Concrete
Length
34 ft
1 main span
Daily traffic
70,011
2013 count
Owner
State
State Highway Agency

About this bridge

Is 70 over Grindstone Run is a concrete arch - deck carrying Is 70 over Grindstone Run in Frederick County, Maryland. It was built in 1968, so it is 57 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 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 70,011 vehicles a day, roughly 8% of them trucks, projected to reach 70,589 by 2026. The structure is 34 ft (10.4 m) long and 30 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesIs 70
CrossesGrindstone Run
Location0.3 Mile West of Md 17
RouteInterstate 70
CountyFrederick County
StateMaryland
Coordinates39.49891, -77.57228
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating110.1 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length34 ft (10.4 m)
Longest span34 ft (10.4 m)
Deck width30 ft (9.2 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic70,011 (2013)
Projected traffic70,589 by 2026
Trucks8%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Is 70 over Grindstone Run built?

It was built in 1968, making it 57 years old in 2025.

What condition is Is 70 over Grindstone Run 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 Is 70 over Grindstone Run carry?

About 70,011 vehicles per day (2013 count), of which roughly 8% are trucks.

How long is Is 70 over Grindstone Run?

The structure is 34 ft (10.4 m) long with a longest span of 34 ft (10.4 m) and a deck 30 ft wide.

Who owns Is 70 over Grindstone Run?

It is owned by the State Highway Agency.