SR 79 over Big Wash

Fair

Pinal County, Arizona · 0.7 MI North JCT SR 77 · Structure no. 00965

Built: 1967; 58 years old
Condition: Fair; inspected February 2024
Type: Slab; Concrete Continuous
Length: 172 ft; 6 main spans
Daily traffic: 3,186; 2023 count
Owner: State; State Highway Agency

About this bridge

SR 79 over Big Wash is a concrete continuous slab carrying SR 79 over Big Wash in Pinal County, Arizona. It was built in 1967, so it is 58 years old, older than the Arizona average of 47.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 3,186 vehicles a day, roughly 11% of them trucks, projected to reach 3,196 by 2042. The structure is 172 ft (52.4 m) long and 35 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

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CarriesSR 79

CrossesBig Wash

Location0.7 MI North JCT SR 77

RouteState Highway 79

CountyPinal County

StateArizona

Coordinates32.56285, -110.93887

Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

Component	Rating	Meaning
Deck	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure	5 Fair	All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure	7 Good	Some minor problems.
Channel and channel protection	7 Good	Some minor problems.

Last inspectionFebruary 2024

Inspection intervalevery 24 months

Operating statusOpen, no restriction

ScourFoundations stable; scour within limits of footing or piles

Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is

Deck geometry4: Meets minimum tolerable limits to be left in place as is

Waterway adequacy7: Better than present minimum criteria

Approach roadway alignment8: Equal to present desirable criteria

Operating rating57 US tons

Inventory rating34 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans6

Design loadHS 20

Structure length172 ft (52.4 m)

Longest span30 ft (9.1 m)

Deck width35 ft (10.7 m)

Roadway width30 ft (9.1 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,186 (2023)

Projected traffic3,196 by 2042

Trucks11%

Lanes on structure2

Traffic directionTwo-way traffic

CarriesHighway

CrossesWaterway

Detour if closed31.7 mi (51 km)

TollOn a free road

National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency

Maintained byState Highway Agency

Historic statusNot eligible for the National Register of Historic Places

Work proposedWidening with deck rehabilitation or replacement

Estimated improvement cost—

NavigationNo navigation control on waterway

Frequently asked questions

When was SR 79 over Big Wash built?

It was built in 1967, making it 58 years old in 2025.

What condition is SR 79 over Big Wash 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 February 2024.

How much traffic does SR 79 over Big Wash carry?

About 3,186 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is SR 79 over Big Wash?

The structure is 172 ft (52.4 m) long with a longest span of 30 ft (9.1 m) and a deck 35 ft wide.

Who owns SR 79 over Big Wash?

It is owned by the State Highway Agency.