US Bridges

I-8 WB over Gillespie Canal

Fair

Maricopa County, Arizona · 8.6 MI W JCT SR 85 · Structure no. 00568

Built
1960
65 years old
Condition
Fair
inspected February 2024
Type
Slab
Concrete Continuous
Length
43 ft
2 main spans
Daily traffic
6,067
2022 count
Owner
State
State Highway Agency

About this bridge

I-8 WB over Gillespie Canal is a concrete continuous slab carrying I-8 WB over Gillespie Canal in Maricopa County, Arizona. It was built in 1960, 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 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 6,067 vehicles a day, roughly 26% of them trucks, projected to reach 6,077 by 2042. The structure is 43 ft (13.1 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-8 WB
CrossesGillespie Canal
Location8.6 MI W JCT SR 85
RouteInterstate 8
CountyMaricopa County
StateArizona
Coordinates32.9232, -112.8785
Functional classRural Principal Arterial - Interstate

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.9 US tons
Inventory rating37 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length43 ft (13.1 m)
Longest span21 ft (6.4 m)
Deck width43 ft (13.1 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,067 (2022)
Projected traffic6,077 by 2042
Trucks26%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-8 WB over Gillespie Canal built?

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

What condition is I-8 WB over Gillespie Canal 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 I-8 WB over Gillespie Canal carry?

About 6,067 vehicles per day (2022 count), of which roughly 26% are trucks.

How long is I-8 WB over Gillespie Canal?

The structure is 43 ft (13.1 m) long with a longest span of 21 ft (6.4 m) and a deck 43 ft wide.

Who owns I-8 WB over Gillespie Canal?

It is owned by the State Highway Agency.