US Bridges

Union Hills Drive over SR 51

Good

Maricopa County, Arizona · 6 MI E I-17 & 1 MI S L101 · Structure no. 01454

Built
2003
22 years old
Condition
Good
inspected October 2023
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete Continuous
Length
189 ft
2 main spans
Daily traffic
23,872
2022 count
Owner
State
State Highway Agency

About this bridge

Union Hills Drive over SR 51 is a prestressed concrete continuous box beam or girders - single or spread carrying Union Hills Drive over SR 51 in Maricopa County, Arizona. It was built in 2003, so it is 22 years old, younger 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 23,872 vehicles a day, roughly 5% of them trucks, projected to reach 23,882 by 2022. The structure is 189 ft (57.6 m) long and 160 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesUnion Hills Drive
CrossesSR 51
Location6 MI E I-17 & 1 MI S L101
RouteCity Street 0
CountyMaricopa County
StateArizona
Coordinates33.6552, -112.0004
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating93 US tons
Inventory rating56 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length189 ft (57.6 m)
Longest span92 ft (28 m)
Deck width160 ft (48.7 m)
Roadway width88 ft (26.8 m)
Vertical clearance over deck20 ft (6.1 m)

Traffic and service

Average daily traffic23,872 (2022)
Projected traffic23,882 by 2022
Trucks5%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed1.9 mi (3 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Union Hills Drive over SR 51 built?

It was built in 2003, making it 22 years old in 2025.

What condition is Union Hills Drive over SR 51 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 2023.

How much traffic does Union Hills Drive over SR 51 carry?

About 23,872 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is Union Hills Drive over SR 51?

The structure is 189 ft (57.6 m) long with a longest span of 92 ft (28 m) and a deck 160 ft wide.

Who owns Union Hills Drive over SR 51?

It is owned by the State Highway Agency.