ICPI Addresses Civil Engineers at PICP Green Alley & Green Streets Seminar

On June 9, North Carolina State University (NCSU) hosted a seminar in Wilson, NC on green alleys consisting of permeable interlocking concrete pavement (PICP). About 30 consulting engineers and representatives from municipal stormwater agencies in the region learned about Wilson building three green alleys to reduce urban runoff damaging local streams. ICPI staff presented on structural design for parking lots, alleys, and streets as provided in ASCE 68-18, a national standard on PICP design. Besides covering construction and maintenance, the program included updates on ongoing runoff and pollution monitoring by NCSU of green street projects in Morrisville and Fayetteville, NC. The University will also be monitoring water infiltrating into Wilson’s green alleys. For Wilson, green alleys represent building blocks among a mix of other public and private sector projects to revitalize the downtown. Taken together, these projects represent the gradual and steady transformation of Wilson’s downtown from a former tobacco mercantile center to mixed residential and retail uses. For the past 20 years, NCSU has been instrumental in providing research and technical support to the state’s Department of Environmental Quality that led to expansion of PICP throughout the state. Wilson’s green alleys were supplied and built by ICPI members.

Initially started by the Chicago Department of Transportation around 2009, dozens of municipalities across the US have since implemented green alleys. These include Washington, DC; Los Angeles, San Francisco and Sacramento, CA; Dubuque, IA; Boston, MA; Nashville, TN; Seattle, WA; Austin, TX; Baltimore, MD and Richmond, VA among others.

The first of three Green Alley Wilson, NC. The next two will be larger and include outdoor living spaces.

ICPI’s Technical Director David R. Smith working through PICP structural design at the Wilson, NC green alley seminar.

Reba Miller