US Bridges

IRR Poston Road over LA Paz Wash

Good

La Paz County, Arizona · 3 MI N JCT I-10 · Structure no. 10375

Built
1960
65 years old, rebuilt 2000
Condition
Good
inspected January 2022
Type
Culvert
Concrete Continuous
Length
87 ft
8 main spans
Daily traffic
1,162
2022 count
Owner
County
County Highway Agency

About this bridge

IRR Poston Road over LA Paz Wash is a concrete continuous culvert carrying IRR Poston Road over LA Paz Wash in La Paz County, Arizona. It was built in 1960 and reconstructed in 2000, so it is 65 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 1,162 vehicles a day, roughly 10% of them trucks, projected to reach 1,172 by 2042. The structure is 87 ft (26.5 m) long and 60 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesIRR Poston Road
CrossesLA Paz Wash
Location3 MI N JCT I-10
RouteCounty Highway 0
CountyLa Paz County
StateArizona
Coordinates33.6384, -114.4935
Functional classRural Major Collector

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 inspectionJanuary 2022
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating35.1 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20
Structure length87 ft (26.5 m)
Longest span10 ft (3 m)
Deck width60 ft (18.3 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,162 (2022)
Projected traffic1,172 by 2042
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 IRR Poston Road over LA Paz Wash built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 2000.

What condition is IRR Poston Road over LA Paz 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 January 2022.

How much traffic does IRR Poston Road over LA Paz Wash carry?

About 1,162 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is IRR Poston Road over LA Paz Wash?

The structure is 87 ft (26.5 m) long with a longest span of 10 ft (3 m) and a deck 60 ft wide.

Who owns IRR Poston Road over LA Paz Wash?

It is owned by the County Highway Agency.