US Bridges

Is 70 E over Grindstone CR

Fair

Boone County, Missouri · S 11 T 48 N R 12 W · Structure no. 6210

Built
1949
76 years old, rebuilt 1978
Condition
Fair
inspected September 2023
Type
Culvert
Concrete Continuous
Length
39 ft
3 main spans
Daily traffic
47,500
2024 count
Owner
State
State Highway Agency

About this bridge

Is 70 E over Grindstone CR is a concrete continuous culvert carrying Is 70 E over Grindstone CR in Boone County, Missouri. It was built in 1949 and reconstructed in 1978, so it is 76 years old, older than the Missouri average of 45.1 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 47,500 vehicles a day, roughly 30% of them trucks, projected to reach 78,375 by 2044. The structure is 39 ft (11.9 m) long. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesIs 70 E
CrossesGrindstone CR
LocationS 11 T 48 N R 12 W
RouteInterstate 70
CountyBoone County
StateMissouri
Coordinates38.96001, -92.23594
Functional classUrban 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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.3 US tons
Inventory rating53.6 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20
Structure length39 ft (11.9 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic47,500 (2024)
Projected traffic78,375 by 2044
Trucks30%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 E over Grindstone CR built?

It was built in 1949, making it 76 years old in 2025. It was reconstructed in 1978.

What condition is Is 70 E over Grindstone CR 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 September 2023.

How much traffic does Is 70 E over Grindstone CR carry?

About 47,500 vehicles per day (2024 count), of which roughly 30% are trucks.

How long is Is 70 E over Grindstone CR?

The structure is 39 ft (11.9 m) long with a longest span of 10 ft (3 m).

Who owns Is 70 E over Grindstone CR?

It is owned by the State Highway Agency.