De-Icing Research Confirms Environmental and Roadway Safety Benefits of Permeable Pavers in Colder Climates

Runoff containing de-icing road salts can potentially harm waterways and biological systems. Because of this, the University of Toronto conducted a two-year study to compare permeable interlocking concrete pavements (PICP) to impervious asphalt surfaces to identify opportunities for minimizing the environmental impact. The study also looked at friction levels to determine the amount of de-icing materials required for each surface to maintain pedestrian and vehicular safety.

The university recently published their findings, De-icing Operations for Permeable Interlocking Concrete Pavements, which not only proved PICP to be more effective, but also identified Best Management Practices for winter operations of PICP.

  • PICP reduced the volume and slowed the release of runoff. PICP discharge never exceeded USEPA chloride concentration limits to sustain aquatic live. Not only did impervious asphalt runoff exceed those limits, the salinity level was five times higher for impervious asphalt versus PICP in winter months.

  • Unlike impervious asphalt, PICP can eliminate snow melt re-freeze and black ice formation due to direct surface infiltration of melted snow.

  • PICP can be treated with lower application rates of de-icing salts to provide equivalent safety levels.

The research was conducted at the Toronto & Region Conservation Authority’s Kortright Centre in Vaughn, Ontario under the direction of Dr. Jennifer Drake at the University of Toronto. The work was funded by Interlocking Concrete Pavement Institute (ICPI) Foundation and Canada’s National Science and Engineering Research Council (NSERC) as part of a collaborative R&D grant.

Click here to download the full report and Best Management Practices.