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Low-Impact Paving What
is low-impact paving?
Low-impact paving is a strategy for reducing
smog-forming emissions from paving roads, fire lanes, parking lots and other
surfaces with asphalt. By using non-petroleum-based paving systems, specially
formulated sealants and coatings, and special design features, communities
can reduce smog-forming emissions of volatile organic compounds (VOCs).
These options provide other environmental benefits, lower construction or
maintenance costs, and can enhance the aesthetics of a project. For every
one acre of low-impact paving, as much as 2 tons of VOC emissions are eliminated
compared to emulsified paving.
Why use alternative paving methods?
Because crude oil is a key ingredient in asphalt,
the manufacture, transport, processing and application of asphalt all contribute
VOCs to regional smog. Many of the coatings, sealants, caulks and markings
required in paving projects are also sources of VOCs. Each summer day in
the Chicago area, more than 13 tons of VOCs are emitted from emulsified
paving projects. Low-impact paving can reduce these emissions and offers
many other benefits.
Improved aesthetics.
Special design options such as reflective surface areas, island planters
and shade trees enhance a projects aesthetic appeal. On Chicagos
Navy Pier, the Chicago Shakespeare Theater installed a rooftop garden area,
paving 1,722 square feet with gray Gravelpave2. The designer filled the
area with small gray gravel to give the impression of an English garden.
The rectangular perimeter features raised planters filled with colorful
flowers.
Enhanced traffic safety.
Reduced surface area, transit design features
and pedestrian amenities have proven effective in reducing traffic speeds
and accidents, thereby extending the life of roadways, reducing air pollution
from traffic and saving pedestrian lives.
Reduced costs.
Some low-impact paving options may allow a project to qualify for zoning
variances that reduce the amount of required parking. Others options include
systems that are more durable and easily repaired than traditional asphalt,
eliminating frequent, expensive and unsightly patching. Some design features
can reduce or eliminate the need to construct stormwater management systems.
In Maryland, the National Archives paved a fire lane and jogging trail with
Grasspave2 to ensure emergency access yet preserve aesthetic harmony with
the wooded forest setting. In communities that assess water and sewage charges
based on impermeable surface area, low-impact paving can lead to lower annual
fees.
How do we implement low-impact paving?
Options for implementing this strategy will vary based on your projects
location, economics, and type. In general, a project will incorporate one
or more of the following key features:
Alternative paving materials.
Several companies have developed paving methods that utilize grass or gravel
as alternatives to asphalt. This option is ideal for overflow and special
use parking facilities. A company called Invisible
Structures outlines several alternatives and provides case studies or
impervious
pavement alternatives.
Minimizing demand for parking.
Local zoning officials can tap the expertise of regional transportation
officials to ensure that new developments incorporate pedestrian-friendly,
transit-oriented design elements and other strategies to minimize the need
to drive. The Regional Transportation Agencys (RTAs) transportation
demand management study is a good resources.
Traffic calming.
Traffic calming design options can reduce the amount of asphalt used, increase
pedestrian travel and decrease vehicle emissions. Traffic calming is the
combination of mainly physical measures that reduce the negative effects
of motor vehicle use, alter driver behavior and improve conditions for non-motorized
street users. municipal
transportation
Heat island reduction.
Due to the lack of trees and use of dark surfaces like roofs and pavements,
most cities have temperatures 2 to 10 degrees hotter than surrounding areas,
hence the term heat island. Parking lot design can incorporate
alternative paving materials, reflective surface coatings, island landscaping
and shade trees to reduce the heat island effect. A model
tree shading ordinance. Sacramento adopted a tree shading ordinance
for parking lots and encourages the use of cooler
paving materials. Another good reference on ways to reduce the heat island
impact of paving are on the City
of Chicagos website.
Is low-impact paving a proven strategy?
Yes.
Dominican University in River Forest recently installed a gravel-paved parking
lot that utilizes an Invisible Structures system. Though the installation
of the lot itself was a little more expensive than blacktop $1.5
million as opposed to $1.25 million there was no need to build a
drainage system, which saved on overall project costs. And since the gravel
could be laid around trees already in the lot, there was no need to remove
or replant them.
In 1997, the Department of Defense (DOD) awarded a contract to repair and
maintain its parking lots and access roads at four Washington, DC, area
facilities. This 5-year, $1 million-per-year project required the contractor
to use recycled content and low VOC products as well as meet DOD's traditional
price and performance specifications. The contractor's products have increased
recycled-content percentages, reduced VOC levels, and lowered overall toxicity.
DOD did not sacrifice cost or performance to achieve its environmental goals.
In fact, the cost was less than if DOD had used traditional paving products
with equivalent performance.
How we measure and report clean air benefits?
Basic information about the type and size of your project and the low-impact
paving options you choose is all you need to calculate your communitys
clean-air benefits. Just call the Clean Air Counts campaign for help.
Reporting
Basic information about the type and size of your project and the low-impact
paving options you choose is all you need to calculate your communitys
clean-air benefits.
Begin Reporting! |
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