N-12 Relieves Congestion
in Surprise Arizona

Surprise, AZ
Installation Date:

Arizona Department of Transportation

Coffman Specialties Inc.

Coffman Specialties Inc.
To alleviate traffic congestion at Bell Road and Grand Avenue in Surprise, AZ, a new overpass and additional roads, lanes and ramps were built. 


The design-build project was given just seven months, between the end of baseball’s spring training and Thanksgiving, for completion.

Railroad tracks near Grand Avenue made realignment of Grand Avenue the best option. Initially, stormwater flow was going to be in a concrete-line open channel between the tracks and Grand Avenue. An alternative was to bury RCP. Instead, 54” (1,350 mm) N-12 was chosen for the twin runs of stormwater pipe. N-12 allowed flows adjacent to the tracks along with Grand Avenue flows to be combined. By running the pipe under

Grand Avenue, it allowed for height reduction of the overpass bridge and shorter ramps.

By using N-12 pipe, the total budget was reduced by 20 percent and the project was able to be completed in time because the N-12 pipe could be installed more quickly.

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