US Bridges

Millbrook Road over Pony Creek

PoorPosted for load

Isabella County, Michigan · 0.4 M W SE Cor Sec 35 T14 · Structure no. 000000000004276

Built
1939
86 years old
Condition
Poor
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
28 ft
1 main span
Daily traffic
56
2002 count
Owner
County
County Highway Agency

About this bridge

Millbrook Road over Pony Creek is a steel stringer/multi-beam or girder carrying Millbrook Road over Pony Creek in Isabella County, Michigan. It was built in 1939, so it is 86 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. Its operating status is: posted for load restriction.

It carries about 56 vehicles a day, projected to reach 85 by 2022. The structure is 28 ft (8.5 m) long and 24 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesMillbrook Road
CrossesPony Creek
Location0.4 M W SE Cor Sec 35 T14
RouteCounty Highway 0
CountyIsabella County
StateMichigan
Coordinates43.55292, -84.99488
Functional classRural Major Collector

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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating38.9 US tons
Inventory rating23.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length28 ft (8.5 m)
Longest span24 ft (7.3 m)
Deck width24 ft (7.3 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic56 (2002)
Projected traffic85 by 2022
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$150,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Millbrook Road over Pony Creek built?

It was built in 1939, making it 86 years old in 2025.

What condition is Millbrook Road over Pony 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 July 2024.

How much traffic does Millbrook Road over Pony Creek carry?

About 56 vehicles per day (2002 count).

How long is Millbrook Road over Pony Creek?

The structure is 28 ft (8.5 m) long with a longest span of 24 ft (7.3 m) and a deck 24 ft wide.

Who owns Millbrook Road over Pony Creek?

It is owned by the County Highway Agency.