US Bridges

Signal Butte Road over Cap Canal

Good

Maricopa County, Arizona · 0.25 MI S of Broadway RD · Structure no. 08861

Built
1985
40 years old
Condition
Good
inspected July 2023
Type
Culvert
Concrete Continuous
Length
132 ft
3 main spans
Daily traffic
20,256
2019 count
Owner
City
City or Municipal Highway Agency

About this bridge

Signal Butte Road over Cap Canal is a concrete continuous culvert carrying Signal Butte Road over Cap Canal in Maricopa County, Arizona. It was built in 1985, so it is 40 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 20,256 vehicles a day, roughly 5% of them trucks, projected to reach 20,266 by 2039. The structure is 132 ft (40.2 m) long and 59 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSignal Butte Road
CrossesCap Canal
Location0.25 MI S of Broadway RD
RouteCity Street 0
CountyMaricopa County
StateArizona
Coordinates33.40139, -111.59806
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47 US tons
Inventory rating28 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length132 ft (40.2 m)
Longest span35 ft (10.7 m)
Deck width59 ft (17.9 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20,256 (2019)
Projected traffic20,266 by 2039
Trucks5%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Signal Butte Road over Cap Canal built?

It was built in 1985, making it 40 years old in 2025.

What condition is Signal Butte Road over Cap Canal 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 July 2023.

How much traffic does Signal Butte Road over Cap Canal carry?

About 20,256 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is Signal Butte Road over Cap Canal?

The structure is 132 ft (40.2 m) long with a longest span of 35 ft (10.7 m) and a deck 59 ft wide.

Who owns Signal Butte Road over Cap Canal?

It is owned by the City or Municipal Highway Agency.