National Asphalt Pavement Association

Research Finds Unintended Consequences of Reflective Pavements

Addressing the urban heat island effect (UHI) is a growing concern for many municipalities, but a new report from Arizona State University (ASU), "Unintended Consequences: A Research Synthesis Examining the Use of Reflective Pavements to Mitigate the Urban Heat Island Effect," calls into question many common assumptions about the ability of reflective pavements to mitigate UHI.

Reflective surfaces redirect solar energy and for this reason high-albedo, reflective, or "cool" roofs have been suggested as an important tool for UHI mitigation. However, efforts to apply the same principle to pavements overlook the complexities of urban geography and how ground-level reflections interact with pedestrians, vehicles, and the built environment.

"We cannot assume that reflective pavements will behave the same as reflective roofs. When energy is reflected from a ground surface, it doesn't return directly to the sky. It reflects back at buildings and pedestrians. Heat concentration in urban areas is a multifaceted problem; it requires a solution that looks at more than just one mitigation strategy," said Heather Dylla, Ph.D., Director of Sustainable Engineering for the National Asphalt Association (NAPA).

A copy of the report can be downloaded from the ASU National Center for SMART Innovations website at http://ncesmart.asu.edu/news/unintended-consequences.

The National Asphalt Pavement Association (NAPA) today (Sept. 11, 2013) presented Sen. Barbara Boxer (D-Calif.) with the Asphalt Legislator of the Year Award for her bipartisan leadership in crafting the Moving Ahead for Progress in the 21st Century Act (MAP-21).

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National Asphalt Pavement Association