US Bridges

Csah 4 over Rock River

Good

Rock County, Minnesota · 0.1 MI E of JCT Csah 18 · Structure no. 67553

Built
2008
17 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
232 ft
3 main spans
Daily traffic
3,350
2018 count
Owner
County
County Highway Agency

About this bridge

Csah 4 over Rock River is a steel continuous stringer/multi-beam or girder carrying Csah 4 over Rock River in Rock County, Minnesota. It was built in 2008, so it is 17 years old, younger than the Minnesota average of 38.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,350 vehicles a day, projected to reach 3,300 by 2038. The structure is 232 ft (70.6 m) long and 54 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesCsah 4
CrossesRock River
Location0.1 MI E of JCT Csah 18
RouteCounty Highway 4
CountyRock County
StateMinnesota
Coordinates43.65409, -96.20111
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating32.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length232 ft (70.6 m)
Longest span86 ft (26.2 m)
Deck width54 ft (16.6 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,350 (2018)
Projected traffic3,300 by 2038
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed8.7 mi (14 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 Csah 4 over Rock River built?

It was built in 2008, making it 17 years old in 2025.

What condition is Csah 4 over Rock River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2024.

How much traffic does Csah 4 over Rock River carry?

About 3,350 vehicles per day (2018 count).

How long is Csah 4 over Rock River?

The structure is 232 ft (70.6 m) long with a longest span of 86 ft (26.2 m) and a deck 54 ft wide.

Who owns Csah 4 over Rock River?

It is owned by the County Highway Agency.