Stewardship practice requires the careful review
of use of sand in areas with the following issues:
[N]
- PM10 (dust) related air quality problems;
- Potential for in spawning streams, shallow lakes
or ponds;
- Sensitive, rare plants near the roadside; and,
- Sand is considered to have a negative impact on
aesthetics.
The Montana Department of Transportation (MDT) and
the Western Transportation Institute have developed "Recommendations
for Winter Traction Materials Management on Roadways
Adjacent to Bodies of Water." [N]
That study and MDT practice recommended the following:
- Identify areas where road sand may be impacting
streams adjacent to highways.[N]
- Wherever possible, a combination of both structural
and non-structural BMPs, or best management practices,
should be employed to minimize the environmental impacts
of winter traction materials. Structural BMPs treat
or mitigate highway runoff after it goes off the roadways,
and non-structural BMPs reduce the amount of traction
materials applied on roadways while maintaining winter
mobility and public safety. Strategies can be implemented
in the domain of technology, management, or both.
- Strategies may vary, depending on the specific
climate, site, and traffic conditions. The crux is
selecting an appropriate suite of BMPs that can function
most effectively for a given set of conditions.
- Despite the challenges of winter conditions, structural
BMPs such as ponds, wetlands, and vegetated swales
and filter strips, can still remove high levels of
sediment from runoff if designed, sited, installed,
and maintained properly.
- The primary non-structural BMPs used to reduce
the use and thus minimize the environmental impacts
of winter traction materials, include: incorporating
environmental staff into construction and maintenance,
proper training of maintenance professionals, erosion
control, snow fences, snow storage, street sweeping,
improved anti-icing and de-icing practices, improved
sanding practices, appropriate application rate, and
snowplow technologies. Among these, anti-icing strategies,
road weather information systems, the Maintenance
Decision Support System, and advanced snowplow technologies
were highly recommended.
In some areas, MDT is trying to more quickly achieve
a bare road, in order to reduce the traction materials
needed. [N]
Since 1989 Caltrans has substantially reduced the
amount of traction sand applied to the highways in
the Lake Tahoe Basin through a combination of deploying
state-of-the-art sanding equipment, operator training,
and the employment of anti-icing strategies. [N]
Caltrans has significantly increased the amount of
sand recovery, mainly due to the deployment and use
of state-of-the-art vactor and sweeper equipment. [N]
The Iowa Department of Transportation and the Iowa
Highway Research Board study on "The
Use of Abrasives in Winter Maintenance" recommends
the following stewardship practices for effective and
minimal use of abrasives on the following categories
of roadways: [N]
- High Speed Urban Roads. For urban streets with
posted speed limits above 30 mph, there is no significant
value in placing abrasives. Research recommends plowing
and applying chemicals to achieve bare pavement.
- Low Speed Urban Roads. For urban streets with
posted speed limits less than 30 mph, there is less
abrasive dispersion. Abrasives should be limited to
parts of the road where motorists must brake, accelerate,
or maneuver. Even then, abrasives should be applied
only when it will likely take a long time to provide
bare pavement.
- Urban Intersections. Urban intersections are relatively
low-speed traffic locations. Abrasives could be placed
if needed. However, they should be used only when
an intersection might be snow or ice-covered beyond
a normal period.
- Rural Roads. Both paved and gravel roads can expect
to see high-speed traffic. Abrasives will not stay
on the road for any reasonable amount of time. Abrasives
should be applied on hills and curves only on low-speed
low-volume roads. Paved rural roads should be plowed
and chemical applied to achieve bare pavement. The
recommended gravel rural roads approach should be
simply to groom the snow pack.
- Rural Intersections. Again, gravel versus paved
roads must be considered. An intersection should
be considered "paved" only if all intersecting
roads are paved. Road segments where motorists must
stop or yield are low-speed traffic locations. Abrasives
could be placed if needed. The preferred approach
for paved roads is to plow and apply chemicals to
achieve bare pavement. On gravel parts of intersections,
abrasives may be applied over that part of the road
where speeds of less than 30 mph are expected.
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