US Bridges

Prophetstown Road over Spring Slough

Fair

Whiteside County, Illinois · 3 MI SW of Rock Fall · Structure no. 098303600000000

Built
1947
78 years old
Condition
Fair
inspected March 2024
Type
Culvert
Steel
Length
24 ft
2 main spans
Daily traffic
2,100
2021 count
Owner
County
County Highway Agency

About this bridge

Prophetstown Road over Spring Slough is a steel culvert carrying Prophetstown Road over Spring Slough in Whiteside County, Illinois. It was built in 1947, so it is 78 years old, older than the Illinois average of 45.3 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 2,100 vehicles a day, roughly 6% of them trucks, projected to reach 2,121 by 2046. The structure is 24 ft (7.3 m) long. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesProphetstown Road
CrossesSpring Slough
Location3 MI SW of Rock Fall
RouteCounty Highway 0
CountyWhiteside County
StateIllinois
Coordinates41.7481, -89.76368
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadUnknown
Structure length24 ft (7.3 m)
Longest span12 ft (3.6 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,100 (2021)
Projected traffic2,121 by 2046
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 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 Prophetstown Road over Spring Slough built?

It was built in 1947, making it 78 years old in 2025.

What condition is Prophetstown Road over Spring Slough 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 March 2024.

How much traffic does Prophetstown Road over Spring Slough carry?

About 2,100 vehicles per day (2021 count), of which roughly 6% are trucks.

How long is Prophetstown Road over Spring Slough?

The structure is 24 ft (7.3 m) long with a longest span of 12 ft (3.6 m).

Who owns Prophetstown Road over Spring Slough?

It is owned by the County Highway Agency.