US Bridges

Kolb Road over Alamo Wash; West Branch

Good

Pima County, Arizona · 0.3 MI N JCT Escalante RD · Structure no. 09517

Built
1965
60 years old, rebuilt 1974
Condition
Good
inspected October 2021
Type
Culvert
Concrete Continuous
Length
29 ft
2 main spans
Daily traffic
33,952
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

Kolb Road over Alamo Wash; West Branch is a concrete continuous culvert carrying Kolb Road over Alamo Wash; West Branch in Pima County, Arizona. It was built in 1965 and reconstructed in 1974, so it is 60 years old, older 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 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 33,952 vehicles a day, roughly 10% of them trucks, projected to reach 33,962 by 2040. The structure is 29 ft (8.8 m) long and 124 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesKolb Road
CrossesAlamo Wash; West Branch
Location0.3 MI N JCT Escalante RD
RouteCity Street 0
CountyPima County
StateArizona
Coordinates32.1827, -110.841
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.
Culvert7 GoodSome minor problems.
Last inspectionOctober 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58 US tons
Inventory rating35.1 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20
Structure length29 ft (8.8 m)
Longest span12 ft (3.7 m)
Deck width124 ft (37.8 m)
Roadway width100 ft (30.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic33,952 (2020)
Projected traffic33,962 by 2040
Trucks10%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Kolb Road over Alamo Wash; West Branch built?

It was built in 1965, making it 60 years old in 2025. It was reconstructed in 1974.

What condition is Kolb Road over Alamo Wash; West Branch 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 October 2021.

How much traffic does Kolb Road over Alamo Wash; West Branch carry?

About 33,952 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Kolb Road over Alamo Wash; West Branch?

The structure is 29 ft (8.8 m) long with a longest span of 12 ft (3.7 m) and a deck 124 ft wide.

Who owns Kolb Road over Alamo Wash; West Branch?

It is owned by the City or Municipal Highway Agency.