US Bridges

Kolb Road over Small Wash

Good

Pima County, Arizona · 100 Ft N of Centennial · Structure no. 08746

Built
1984
41 years old
Condition
Good
inspected November 2023
Type
Culvert
Concrete Continuous
Length
32 ft
3 main spans
Daily traffic
17,598
2023 count
Owner
County
County Highway Agency

About this bridge

Kolb Road over Small Wash is a concrete continuous culvert carrying Kolb Road over Small Wash in Pima County, Arizona. It was built in 1984, so it is 41 years old, younger than the Arizona average of 47.8 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 17,598 vehicles a day, roughly 10% of them trucks, projected to reach 17,608 by 2042. The structure is 32 ft (9.8 m) long. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesKolb Road
CrossesSmall Wash
Location100 Ft N of Centennial
RouteCounty Highway 0
CountyPima County
StateArizona
Coordinates32.13372, -110.8409
Functional classUrban Other Principal Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert8 Very GoodNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating110.1 US tons
Inventory rating83 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20
Structure length32 ft (9.8 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,598 (2023)
Projected traffic17,608 by 2042
Trucks10%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Kolb Road over Small Wash built?

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

What condition is Kolb Road over Small Wash 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 2023.

How much traffic does Kolb Road over Small Wash carry?

About 17,598 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Kolb Road over Small Wash?

The structure is 32 ft (9.8 m) long with a longest span of 10 ft (3 m).

Who owns Kolb Road over Small Wash?

It is owned by the County Highway Agency.