Scott Rogers, director of operations, Vermont Agency of Transportation
updated
Wed, Jan 25, 2012 01:37 PM
Like our neighboring states, Vermont adheres to a "Safe Roads at
Safe Speeds" policy during storm events. Delivering "bare roads"
during a storm is simply not possible. However, we are constantly
working to deploy new technologies and methods to improve safety
for the traveling public and efficiency in the expenditure of their
tax dollars.
One new initiative that has been garnering more attention lately is
the use of salt brine. It's important that the public understand
what salt brine is and how it differs-or doesn't- from conventional
road salt.
Road salt is the same as the salt on the dinner table, NaCl, just
bigger particles and not as clean. Salt brine is nothing more
than salt and water, NaCl and H2O. You can drop dry salt particles
in a pile of snow, or mix dry salt particles with water to make
salt brine - you end up with the exact same thing, salt and
water. In fact, our salt brine is made with the same salt -
from the same stockpiles - that we are already spreading on the
highways.
At times VTrans will mix additives into dry salt or salt brine to
make the salt work better at lower temperatures. We mostly
use a product called Ice B' Gone that is essentially water,
molasses and magnesium chloride (which is just another kind of
salt). Ice B' Gone also makes the salt or brine sticky so it
stays on the road better and has been documented by our own field
testing, as well as other organizations such as the Pacific
Northwest Snowfighters Association, to be less corrosive than
salt. In fact, Ice B' Gone is rated by the EPA as being
"Designed for the Environment".
The use of sand and chlorides has a cumulative, detrimental effect
on the environment. When we allow sand and salt into our water
ecosystems it doesn't break down or disappear; it stays there until
it's removed. Since large-scale removal is not technologically or
economically feasible, it behooves us to limit the amount of sand
and salt entering the environment. That is precisely the aim of the
salt brine effort - it allows us to use less sand and salt while
still providing a safe road for travelers.
In the winter of 2000-2001, for example, total snowfall in
Burlington was 122 inches. The maintenance district used 16,540
tons of salt and 9,180 cubic yards of sand to maintain the state
highways within their jurisdiction. During the winter of 2010-2011,
Burlington saw 128 inches of snow and that same district, using
salt-brine, used about 11,000 tons of salt and just 7 cubic yards
of sand. The savings of 5,540 tons of salt and 9,170 cubic yards of
sand is due - at least in part - to the use of salt brine and salt
brine blends.
VTrans is confident that continued research, training and
experience, will assist in the achievement of even greater savings
without sacrificing safety.
Some have expressed concern that salt brine is somehow harder on
cars than conventional road salt. Salt brine is the same chemical
composition as dry salt mixed with ice, snow or rain. Less
salt used translates into less corrosion potential regardless of
whether it is dry salt or wet salt (brine).
Studies have shown that the additive blends we use actually lower
the corrosive properties of salt. The Margaret Chase Smith Policy
Center at the University of Maine also tackled this question. They
came to the conclusion that the total number of chlorides in the
environment has a much stronger influence on metal corrosion than
the type of chloride-based deicer or the method of application.
While there may be individuals who speculate that salt brine is
more corrosive to vehicles, the science and studies to date have
not shown this to be true.
Our goal is to perform winter maintenance activities in the most
safe, cost effective and environmentally friendly manner possible,
and we believe salt brine is one of the tools which will allow us
to do just that. But no matter what combination of tools and
methods we employ in our effort to manage road conditions, public
safety on our highways still depends largely on the behavior of
individual drivers and the collective willingness to slow down when
conditions warrant it.
In the end, the safety of everyone on the road depends on the
choices you make.
Tagged:
salt brine, VTrans
