US Bridges

US166 HWY EB over Onion Creek

Good

Montgomery County, Kansas · 13.79 MI E Sjct US75 EB · Structure no. 999916600630391

Built
1970
55 years old
Condition
Good
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
293 ft
4 main spans
Daily traffic
2,627
2023 count
Owner
State
State Highway Agency

About this bridge

US166 HWY EB over Onion Creek is a steel continuous stringer/multi-beam or girder carrying US166 HWY EB over Onion Creek in Montgomery County, Kansas. It was built in 1970, so it is 55 years old, older than the Kansas average of 52.8 years.

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

It carries about 2,627 vehicles a day, roughly 11% of them trucks, projected to reach 2,680 by 2044. The structure is 293 ft (89.3 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesUS166 HWY EB
CrossesOnion Creek
Location13.79 MI E Sjct US75 EB
RouteU.S. Route 166
StateKansas
Coordinates37.03639, -95.68222
Functional classRural Principal Arterial - Other

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68 US tons
Inventory rating41 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length293 ft (89.3 m)
Longest span80 ft (24.4 m)
Deck width42 ft (12.8 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,627 (2023)
Projected traffic2,680 by 2044
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was US166 HWY EB over Onion Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is US166 HWY EB over Onion Creek 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 March 2023.

How much traffic does US166 HWY EB over Onion Creek carry?

About 2,627 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US166 HWY EB over Onion Creek?

The structure is 293 ft (89.3 m) long with a longest span of 80 ft (24.4 m) and a deck 42 ft wide.

Who owns US166 HWY EB over Onion Creek?

It is owned by the State Highway Agency.