US Bridges

I-8 Sfr over Gillespie Canal

Fair

Maricopa County, Arizona · 8.6 MI W JCT SR 85 · Structure no. 01009

Built
1923
102 years old, rebuilt 1949
Condition
Fair
inspected February 2024
Type
Slab
Concrete Continuous
Length
45 ft
2 main spans
Daily traffic
368
2022 count
Owner
State
State Highway Agency

About this bridge

I-8 Sfr over Gillespie Canal is a concrete continuous slab carrying I-8 Sfr over Gillespie Canal in Maricopa County, Arizona. It was built in 1923 and reconstructed in 1949, so it is 102 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 368 vehicles a day, roughly 2% of them trucks, projected to reach 378 by 2042. The structure is 45 ft (13.7 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-8 Sfr
CrossesGillespie Canal
Location8.6 MI W JCT SR 85
RouteState Highway 8
CountyMaricopa County
StateArizona
Coordinates32.9225, -112.87889
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry9: Superior to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating41 US tons
Inventory rating24 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length45 ft (13.7 m)
Longest span22 ft (6.7 m)
Deck width48 ft (14.6 m)
Roadway width45 ft (13.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic368 (2022)
Projected traffic378 by 2042
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$1,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-8 Sfr over Gillespie Canal built?

It was built in 1923, making it 102 years old in 2025. It was reconstructed in 1949.

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

About 368 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is I-8 Sfr over Gillespie Canal?

The structure is 45 ft (13.7 m) long with a longest span of 22 ft (6.7 m) and a deck 48 ft wide.

Who owns I-8 Sfr over Gillespie Canal?

It is owned by the State Highway Agency.