US Bridges

Petersburg RD over Swamp Raisin Drain

Fair

Monroe County, Michigan · 1.25 MI S of M-50 · Structure no. 000000000007233

Built
1956
69 years old, rebuilt 2019
Condition
Fair
inspected May 2023
Type
Box Beam or Girders - Single or Spread
Steel
Length
40 ft
1 main span
Daily traffic
500
2016 count
Owner
County
County Highway Agency

About this bridge

Petersburg RD over Swamp Raisin Drain is a steel box beam or girders - single or spread carrying Petersburg RD over Swamp Raisin Drain in Monroe County, Michigan. It was built in 1956 and reconstructed in 2019, so it is 69 years old, older than the Michigan average of 48.3 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 500 vehicles a day, roughly 17% of them trucks, projected to reach 575 by 2036. The structure is 40 ft (12.2 m) long and 31 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesPetersburg RD
CrossesSwamp Raisin Drain
Location1.25 MI S of M-50
RouteCounty Highway 5815
CountyMonroe County
StateMichigan
Coordinates41.94717, -83.71155
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating85 US tons
Inventory rating65.7 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialSteel
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length40 ft (12.2 m)
Longest span35 ft (10.6 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic500 (2016)
Projected traffic575 by 2036
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Petersburg RD over Swamp Raisin Drain built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 2019.

What condition is Petersburg RD over Swamp Raisin Drain 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 May 2023.

How much traffic does Petersburg RD over Swamp Raisin Drain carry?

About 500 vehicles per day (2016 count), of which roughly 17% are trucks.

How long is Petersburg RD over Swamp Raisin Drain?

The structure is 40 ft (12.2 m) long with a longest span of 35 ft (10.6 m) and a deck 31 ft wide.

Who owns Petersburg RD over Swamp Raisin Drain?

It is owned by the County Highway Agency.