US Bridges

T 18 over Rock River

PoorPosted for load

Pipestone County, Minnesota · 0.4 MI E of JCT Csah 17 · Structure no. 59519

Built
1984
41 years old
Condition
Poor
inspected October 2024
Type
Slab
Wood or Timber
Length
116 ft
4 main spans
Daily traffic
22
1986 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

T 18 over Rock River is a wood or timber slab carrying T 18 over Rock River in Pipestone County, Minnesota. It was built in 1984, so it is 41 years old, older than the Minnesota average of 38.5 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 22 vehicles a day, projected to reach 22 by 2029. The structure is 116 ft (35.4 m) long and 26 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesT 18
CrossesRock River
Location0.4 MI E of JCT Csah 17
RouteCounty Highway 18
CountyPipestone County
StateMinnesota
Coordinates43.93571, -96.13624
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 protection3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.8 US tons
Inventory rating33.1 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans4
Design loadHS 20
Structure length116 ft (35.4 m)
Longest span32 ft (9.8 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22 (1986)
Projected traffic22 by 2029
Trucks—
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

OwnerTown or Township Highway Agency
Maintained byTown or Township Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$800 million (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was T 18 over Rock River built?

It was built in 1984, making it 41 years old in 2025.

What condition is T 18 over Rock 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 October 2024.

How much traffic does T 18 over Rock River carry?

About 22 vehicles per day (1986 count).

How long is T 18 over Rock River?

The structure is 116 ft (35.4 m) long with a longest span of 32 ft (9.8 m) and a deck 26 ft wide.

Who owns T 18 over Rock River?

It is owned by the Town or Township Highway Agency.