Designed to allow stormwater to drain directly through the paved surface and percolate into the subbase, these pavements are winning favor in environmentally-sensitive areas and in developments where space for water retention is at a premium.

Where the technologies of the two industries clash, the conflict is almost always about cost-effectiveness and service life, and sustainability usually benefits from the competition.

They have become an important option for parking lot design, but road agencies are finding creative applications for them, too, from the City of Chicago’s “Green Alley” — a program which employs pervious concrete or porous asphalt for alleys to mitigate storm water run-off — to California’s experimentation with porous asphalt for road shoulders to enhance water quality.

No matter what pavement material is used, a significant factor in the sustainability of any pavement depends on the ability of pavement engineers to stay current with – and open-minded about – advances in materials, technologies and techniques that lower costs and enhance the environment.

Advocates for asphalt and concrete alike focus much of their efforts on communicating best practices to DOT and consulting engineers.

Often times, the best-practices message regards technology that has been proven in one place, but not adopted in many others.

For Leif Wathne and ACPA, one example of this is educating the road industry on today’s best practices for partial-depth repairs of concrete joints. While construction delays caused by concrete or asphalt pavement maintenance are a relatively small portion of the pavement sustainability picture, reducing repair times improves service to the motorist and usually reduces costs – and reduces carbon emissions from traffic slowdowns.

“This isn’t magic pixie dust,” Wathne says of ACPA’s Partial Depth Repair of Concrete Pavements. “This is proven process and methodology from states that have developed real expertise in this area, incorporating newer technologies like precision mills to get the job done more efficiently.”