US Bridges

IRR SR 85 over Gibson Wash

Good

Pima County, Arizona · 41.4 MI S JCT B 8 · Structure no. 04579

Built
1944
81 years old
Condition
Good
inspected October 2021
Type
Culvert
Concrete Continuous
Length
32 ft
3 main spans
Daily traffic
2,777
2020 count
Owner
State
State Highway Agency

About this bridge

IRR SR 85 over Gibson Wash is a concrete continuous culvert carrying IRR SR 85 over Gibson Wash in Pima County, Arizona. It was built in 1944, so it is 81 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 2,777 vehicles a day, roughly 11% of them trucks, projected to reach 2,787 by 2040. The structure is 32 ft (9.8 m) long and 51 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesIRR SR 85
CrossesGibson Wash
Location41.4 MI S JCT B 8
RouteState Highway 85
CountyPima County
StateArizona
Coordinates32.3779, -112.8724
Functional classRural Minor 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 protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry6: Equal to present minimum 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
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length32 ft (9.8 m)
Longest span10 ft (3 m)
Deck width51 ft (15.5 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,777 (2020)
Projected traffic2,787 by 2040
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR SR 85 over Gibson Wash built?

It was built in 1944, making it 81 years old in 2025.

What condition is IRR SR 85 over Gibson 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 October 2021.

How much traffic does IRR SR 85 over Gibson Wash carry?

About 2,777 vehicles per day (2020 count), of which roughly 11% are trucks.

How long is IRR SR 85 over Gibson Wash?

The structure is 32 ft (9.8 m) long with a longest span of 10 ft (3 m) and a deck 51 ft wide.

Who owns IRR SR 85 over Gibson Wash?

It is owned by the State Highway Agency.