Loop 202: Red Mountain Freeway

Location: Phoenix, AZ
Client: ADOT
Status: Completed


The Loop 202 (202L) Red Mountain Freeway is part of the Maricopa Association of Governments (MAG) Regional Freeway System that connects Interstate 10 (I10) to the Superstition Freeway (US 60). The Arizona Department of Transportation (ADOT) retained Parsons Brinkerhoff (PB) to prepare the design for the new construction of the Red Mountain Freeway between University Drive and Southern Avenue in Mesa, Arizona.

NCSG performed the geotechnical investigations under subcontract to PB and provided recommendations for various structures including three (3) bridges, five (5) retaining walls totaling nearly 4,200 linear feet, a drainage channel paralleling the corridor, as well as pavement design. The field investigation program included 116 borings and 8 large test pits.

During preliminary investigations, an earth fissure crevice was identified that crosses the centerline of the project alignment. Even though the fissure is assumed to be inactive at this moment, it is not possible to assess whether or not it will become active in the future, which could possibly lead to differential settlements of adjacent structures. Hence remedial measure had to be taken to alleviate potential future problems including geocomposites drains, geogrid-reinforced soil platforms, welded wire mat platforms, etc.

This project has been completed and is in service.