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 below.
Related HowStuffWorks Articles
More Great Links
- Adams, Michele C. "Porous Asphalt Pavement With Recharge Beds: 20 Years and Still Working." Stormwater. May/June 2003. (May 13, 2008) http://www.stormcon.com/sw_0305_porous.html
- Boston Metropolitan Area Planning Council. "Low Impact Development Fact Sheet: Permeable Paving." 2008. (May 13, 2008) http://www.mapc.org/regional_planning/LID/permeable_paving.html
- Daley, Richard M. and Heramb, Cheri. "The Chicago Green Alley Handbook." 2007. (May 12, 2008) http://gmcgardenclub.org/images/stories/news/greenalleyhandbook.pdf
- Federal Highway Administration. "The National Highway System." April 29, 2008. (May 8, 2008) http://www.fhwa.dot.gov/planning/nhs/
- Georgia Asphalt Pavement Association. "Asphalt Pavement - Georgia's Green Pavement." 2008. (May 9, 2008) http://www.gahotmix.com/asphalt-environment.aspx
- Grassy Pavers. "Grassy Pavers." 2008. (May 12, 2008) http://www.grassypavers.com/
- Green Highways Partnership. "About GHP." 2007. (May 13, 2008) http://www.greenhighways.org/dev/index.cfm
- Green Highways Partnership. "Environmentally Friendly Concrete." 2007. (May 13, 2008) http://www.greenhighways.org/Template.cfm?FrontID=5105
- Green Resource Center. "Permeable Pavement." July 22, 2004. (May 9, 2008) http://www.greenresourcecenter.org/MaterialSheetsWord/PermeablePaving.pdf
- HGTV. "Green Driveway." 2008. (May 8, 2008) http://www.hgtv.com/hgtv/gl_landscaping_design/article/0,1785,HGTV_3596_1377777,00.html
- Invisible Structures, Inc. "Comparison of Grass Paving Products." July 2003. (May 12, 2008) http://www.grasspave.com/GP2/GP2Compared.htm
- Metropolitan Government of Nashville and Davidson County, Tennessee. "Stormwater - Best Management Practices Manual - Volume 4." 2008. (May 20, 2008) http://www.nashville.gov/stormwater/regs/SwMgt_ManualVol04_2006.htm
- National Asphalt Pavement Association. "Asphalt Pavement is the Surprise Leader in Recycling of Various Materials." 2004. (May 9, 2008) http://www.hotmix.org/recycling.php
- National Asphalt Pavement Association. "History of Asphalt." 2004. (May 9, 2008) http://www.hotmix.org/history.php
- Netlon Turf Systems. "Advanced Turf." October 2000. (May 8, 2008) http://www.netlon.co.uk/_turfsystems/casestudies/Case-Study_AdvTurf3.pdf
- Pervious Concrete. "Environmental Benefits." 2008. (May 9, 2008) http://www.perviouspavement.org/benefits,%20environmental.htm
- Radick, Lea. "Where green hits beyond the baseball field." Medill Reports. April 17, 2008. (May 12, 2008) http://news.medill.northwestern.edu/chicago/news.aspx?id=86295
- United States Green Building Council. "LEED: Project Certification." 2008. (May 20, 2008) http://www.usgbc.org/DisplayPage.aspx?CMSPageID=64