Permeable paving surfaces keep the pollutants in place in the soil or other material underlying the roadway, and allow water seepage to recharge groundwater while preventing the stream erosion problems.

The third, sometimes called open paving, involves the use of generally impermeable materials, but these are placed to maintain open space between them, as in the "hopsack" method, to allow permeable areas of soils or other fill between the material placed. "Hopsack" is a method of placing oblong blocks so that space is permanently maintained between them. Special spacers are also available on the market. Open-type paving is usually intended for applications where grass will grow in the spaces between the blocks or other materials. This is a highly desirable feature in parking areas and low-impact roadways, being esthetically more pleasing, and has the additional benefit of reducing summer heat buildup due to inert pavement materials absorbing solar radiation and reradiating it as ambient heat.