US Bridges

9 Mile Road over Thornton Creek

Poor

Oakland County, Michigan · 0.5 MI W of Novi RD · Structure no. 000000000014274

Built
1970
55 years old
Condition
Poor
inspected September 2024
Type
Culvert
Steel
Length
27 ft
2 main spans
Daily traffic
8,260
2014 count
Owner
City
City or Municipal Highway Agency

About this bridge

9 Mile Road over Thornton Creek is a steel culvert carrying 9 Mile Road over Thornton Creek in Oakland County, Michigan. It was built in 1970, so it is 55 years old, older than the Michigan average of 48.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 8,260 vehicles a day, projected to reach 9,500 by 2034. The structure is 27 ft (8.1 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries9 Mile Road
CrossesThornton Creek
Location0.5 MI W of Novi RD
RouteCity Street 0
CountyOakland County
StateMichigan
Coordinates42.45186, -83.4841
Functional classUrban Minor Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating72.5 US tons
Inventory rating43.5 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadUnknown
Structure length27 ft (8.1 m)
Longest span12 ft (3.7 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,260 (2014)
Projected traffic9,500 by 2034
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 9 Mile Road over Thornton Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is 9 Mile Road over Thornton Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does 9 Mile Road over Thornton Creek carry?

About 8,260 vehicles per day (2014 count).

How long is 9 Mile Road over Thornton Creek?

The structure is 27 ft (8.1 m) long with a longest span of 12 ft (3.7 m).

Who owns 9 Mile Road over Thornton Creek?

It is owned by the City or Municipal Highway Agency.