US Bridges

Csah 18 over Straight River

Fair

Steele County, Minnesota · 0.1 MI W of JCT TH35W · Structure no. 74510

Built
1966
59 years old
Condition
Fair
inspected November 2024
Type
Slab
Prestressed Concrete
Length
92 ft
2 main spans
Daily traffic
990
2019 count
Owner
County
County Highway Agency

About this bridge

Csah 18 over Straight River is a prestressed concrete slab carrying Csah 18 over Straight River in Steele County, Minnesota. It was built in 1966, so it is 59 years old, older than the Minnesota average of 38.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 990 vehicles a day, projected to reach 1,400 by 2039. The structure is 92 ft (27.9 m) long and 31 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesCsah 18
CrossesStraight River
Location0.1 MI W of JCT TH35W
RouteCounty Highway 18
CountySteele County
StateMinnesota
Coordinates44.0516, -93.2524
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 rating77.8 US tons
Inventory rating47.5 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadH 20
Structure length92 ft (27.9 m)
Longest span44 ft (13.5 m)
Deck width31 ft (9.3 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic990 (2019)
Projected traffic1,400 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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$45 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Csah 18 over Straight River built?

It was built in 1966, making it 59 years old in 2025.

What condition is Csah 18 over Straight River 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 November 2024.

How much traffic does Csah 18 over Straight River carry?

About 990 vehicles per day (2019 count).

How long is Csah 18 over Straight River?

The structure is 92 ft (27.9 m) long with a longest span of 44 ft (13.5 m) and a deck 31 ft wide.

Who owns Csah 18 over Straight River?

It is owned by the County Highway Agency.