US Bridges

SR 79 over Olsen Wash

Fair

Pinal County, Arizona · 13.3 MI North JCT SR 77 · Structure no. 00224

Built
1939
86 years old
Condition
Fair
inspected February 2024
Type
Slab
Concrete Continuous
Length
101 ft
4 main spans
Daily traffic
35
2023 count
Owner
State
State Highway Agency

About this bridge

SR 79 over Olsen Wash is a concrete continuous slab carrying SR 79 over Olsen Wash in Pinal County, Arizona. It was built in 1939, so it is 86 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 6 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 35 vehicles a day, roughly 10% of them trucks, projected to reach 45 by 2042. The structure is 101 ft (30.8 m) long and 31 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

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CarriesSR 79
CrossesOlsen Wash
Location13.3 MI North JCT SR 77
RouteState Highway 79
CountyPinal County
StateArizona
Coordinates32.6938, -111.0854
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.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41 US tons
Inventory rating25 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length101 ft (30.8 m)
Longest span25 ft (7.6 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2023)
Projected traffic45 by 2042
Trucks10%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 79 over Olsen Wash built?

It was built in 1939, making it 86 years old in 2025.

What condition is SR 79 over Olsen 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 Olsen Wash carry?

About 35 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is SR 79 over Olsen Wash?

The structure is 101 ft (30.8 m) long with a longest span of 25 ft (7.6 m) and a deck 31 ft wide.

Who owns SR 79 over Olsen Wash?

It is owned by the State Highway Agency.