US Bridges

Summerton Road over Contrib S Br Salt River

PoorPosted for load

Isabella County, Michigan · Sec 18 W Denver Twp · Structure no. 000000000004354

Built
1937
88 years old
Condition
Poor
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
36 ft
1 main span
Daily traffic
185
2002 count
Owner
County
County Highway Agency

About this bridge

Summerton Road over Contrib S Br Salt River is a steel stringer/multi-beam or girder carrying Summerton Road over Contrib S Br Salt River in Isabella County, Michigan. It was built in 1937, so it is 88 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 185 vehicles a day, projected to reach 225 by 2022. The structure is 36 ft (10.9 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesSummerton Road
CrossesContrib S Br Salt River
LocationSec 18 W Denver Twp
RouteCounty Highway 0
CountyIsabella County
StateMichigan
Coordinates43.6921, -84.72798
Functional classRural Local

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.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJune 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.5 US tons
Inventory rating19.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckOther
Main spans1
Design loadH 15
Structure length36 ft (10.9 m)
Longest span32 ft (9.7 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic185 (2002)
Projected traffic225 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$172,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Summerton Road over Contrib S Br Salt River built?

It was built in 1937, making it 88 years old in 2025.

What condition is Summerton Road over Contrib S Br Salt River 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 June 2024.

How much traffic does Summerton Road over Contrib S Br Salt River carry?

About 185 vehicles per day (2002 count).

How long is Summerton Road over Contrib S Br Salt River?

The structure is 36 ft (10.9 m) long with a longest span of 32 ft (9.7 m) and a deck 22 ft wide.

Who owns Summerton Road over Contrib S Br Salt River?

It is owned by the County Highway Agency.