While green pavement has promise, it also has several significant drawbacks.
For one thing, pavers can pose a problem for snowplows. Because pavers are not a smooth surface -- pavers can be a plastic honeycomb shape or concrete blocks with spaces in between -- a plow blade can catch on the edge of the plastic or block and rip it up. One way to resolve this problem is to install a roller on the plow blade, which allows the blade to roll over any uneven portions of the pavement.
Porous/permeable pavement is more expensive to install than traditional pavement. Proponents point out, however, that the need for less drainage piping and other storm water management materials can offset that extra expense.
Permeable pavement is also prone to clogging. Its maintenance demands are different from traditional pavement. If not maintained properly (with an industrial vacuum), sand and other fine sediments can block the spaces between pavers. To prevent this problem, the pavement needs to be vacuumed or pressure-washed at least twice a year. (Obviously, if it were used for public roads, governments would have to come up with equipment and manpower to handle its special maintenance requirements.) Sanding for ice during the winter months can contribute to clogging. If left unchecked, clogging will cause storm water and other pollutants to run off, negating the purpose of the installation [sources: Metropolitan Area Planning Council and Stormwater].
In addition, porous pavement isn't as strong as traditional pavement. Consistent pressure, such as heavy vehicle braking, can collapse the pores of the pavement, causing it to fail. Therefore, the pavement is not advised for things like airport runways or highways (especially those with heavy truck traffic). Currently, it is recommended only for flat areas or those with gentle slopes, where constant high-pressure braking is not an issue [source: Government of Nashville]. However, more reinforced versions of permeable pavement are in development.
To learn more about green pavement and other green trends, read the links on the next page.