US Bridges

I 90 over Bnnr Rr; Csah 4

Fair

Rock County, Minnesota · 2.9 MI E of JCT TH 23 · Structure no. 9689

Built
1964
61 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
388 ft
5 main spans
Daily traffic
5,100
2014 count
Owner
State
State Highway Agency

About this bridge

I 90 over Bnnr Rr; Csah 4 is a prestressed concrete stringer/multi-beam or girder carrying I 90 over Bnnr Rr; Csah 4 in Rock County, Minnesota. It was built in 1964, so it is 61 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 5,100 vehicles a day, roughly 12% of them trucks, projected to reach 5,100 by 2039. The structure is 388 ft (118.2 m) long and 43 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesI 90
CrossesBnnr Rr; Csah 4
Location2.9 MI E of JCT TH 23
RouteInterstate 90
Coordinates43.60862, -96.37619
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72.4 US tons
Inventory rating42.8 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length388 ft (118.2 m)
Longest span78 ft (23.7 m)
Deck width43 ft (13.1 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,100 (2014)
Projected traffic5,100 by 2039
Trucks12%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 90 over Bnnr Rr; Csah 4 built?

It was built in 1964, making it 61 years old in 2025.

What condition is I 90 over Bnnr Rr; Csah 4 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 October 2023.

How much traffic does I 90 over Bnnr Rr; Csah 4 carry?

About 5,100 vehicles per day (2014 count), of which roughly 12% are trucks.

How long is I 90 over Bnnr Rr; Csah 4?

The structure is 388 ft (118.2 m) long with a longest span of 78 ft (23.7 m) and a deck 43 ft wide.

Who owns I 90 over Bnnr Rr; Csah 4?

It is owned by the State Highway Agency.