Evaluation of a New Anti-Icing
During the winters of
1996-1998, a new liquid anti-icing agent was introduced in various
regions of BC. The chemicals involved are environmentally safer and
cost-effective. A significant reduction in crash-related claims was
recorded during their use. BC continues to lead the country in
researching this proactive winter maintenance tool.
Have trouble skidding and
sliding in the winter? Do you cringe every time you see the
salt truck go by, thinking of the holes it will eat in your vehicle,
remembering the plants and animals the salt will affect when it
washes off into the ditches? Do you have stone chips in your
windshield as a reminder of the last snowstorm when the gravel truck
went by? Ever been involved in a crash because of "black ice" on the
road? Well, take heart. Research is currently underway to find
better ways to keep our roads safer.The
way it's always been:
ICBC is taking a serious look at winter road
safety methods. If you spend any time watching a major roadway in BC
during the winter, you will witness a common scenario.
- During a
snowfall, a plow will pass by to scrape most of the
accumulated snow off the road surface.
after, heavy trucks laden with salt, sand or gravel will
follow, throwing large amounts of these substances onto the road.
- If the snow
continues, another plow passes by, scraping away the new
snow and whatever that truck had just applied.
- Another truck
arrives to re-apply what the plow has just scraped
away — the scenario repeats itself over and over, until the
If you live in Kamloops, though, you may have
witnessed a different scene in the past few years. Just before a
winter storm, you may have seen what looked like a water truck,
spraying the road surface. Expecting the road to turn into a sheet
of ice, you would have been surprised to discover that instead, the
roadway remained free of snow buildup. The solution being
sprayed on the road was not water, but a new anti-icing liquid
currently being tested by ICBC.Two methods
of ice control
Since 1996, ICBC has tested two main methods of
ice control known as pre-wetting and anti-icing.
- In the pre-wetting
process, liquid chemicals are
added to existing salt and sand before they are spread on the
road. This helps reduce the ice build-up, and decreases
the amount of salt and aggregate needed.
- In the anti-icing
process, a liquid chemical is applied to the bare road at a
specific time before an expected snowfall. It begins melting snow
and ice immediately to prevent ice from bonding to the pavement.
Do Anti-icers Work?
While many North American agencies have reported
fewer collisions when anti-icers were used, none have reported how
large these benefits actually are.
Safe are Anti-icing Chemicals?
- ICBC Corporate
Research compared data collected from the Kamloops study
area with records from the previous 10 years.
- The study
showed that the average number of crashes on days with snow
or ice was 8% lower than expected during the study period (when
the anti-icing agent was used) than during the ten years prior
(when no anti-icing agent was used).
- From the
data, it was estimated that the agent prevented 285-306
crashes over the three-year period, or a saving of 95-102
crashes per year.
Traditional salt used on icy roads is made up of
- Depending on
factors such as soil permeability and slope of the land,
the sodium and chloride ions can be washed towards the roots of
trees and plants.
- These ions build
up in the twigs and leaves of trees, and may become toxic.
- Extra ions in the
soil may also interfere with a plant's ability to absorb
moisture or other necessary nutrients.
- With certain species
of vegetation, the results can be very serious. In the
early 1970's for example, New Hampshire suffered the loss of
14,000 trees along 3700 miles of salt-treated highways.
In contrast, liquid anti-icers
contain magnesium chloride or calcium chloride.
- Magnesium and
calcium are minerals essential for plant growth.They are
found naturally in soil and water, and are tolerated in high
levels by most plants.
- In Finland,
studies showed that reindeer are not attracted to magnesium and
calcium as they are to the sodium in road salt.
Few complete research studies have been done
on the environmental effects of liquid anti-icers. ICBC commissioned
Levelton Engineering Ltd. to perform extensive research and
laboratory toxicity testing on all potential chemical de-icers.
Levelton's March 1999 report concluded,
"that applications at recommended rates for anti-icing should
pose very little risk to vertebrates, invertebrates or plants."
Effects on cars
Anti-icing chemicals have also proven to have
fewer negative effects on automobiles.
- Magnesium and
calcium chlorides are less corrosive than sodium.
- The anti-icing
solution being used also contains an organic corrosion
inhibitor, so does not contribute to vehicle rusting.
- The use of
anti-icing chemicals also significantly reduces the amount
of sand and gravel on the roads.
- Loose gravel
applied for traction during the winter causes stone chips and
cracked windshields after the winter season has passed.
Areas in North America where anti-icing chemicals
are used report a 10% to 75% reduction in the use of sand and
In the Future
- For example,
the City of Kamloops said they use 50% less sand, and the City of
Kelowna reported they use 40% less.
A variety of anti-icing chemicals have been
used for more than 20 years in Europe, and for about 9 years in the
United States. In Canada, some provinces have tested pre-wetting
agents, but consistent use of anti-icers has not yet been
ICBC piloted the use of liquid anti-icers in
Kamloops during the winter of 1995/96. Vernon (in partnership with
the Ministry of Transportation and Highways) and Kelowna were added
to the project in 1998/99. Since then, the project has been expanded
to include additional communities across the province:
Fort St. John
ICBC provided $1.6 million in grants and training
for the testing and use of liquid anti-icers.
- As of 2000, 85% of the highway contractors in the province were
using pre-wetting, anti-icing or both methods to reduce slippery
Financial benefits of the program in the form of
reduced claims are expected to be two to five times the investment
in the study. Potential benefits of reduced injuries and reduced
environmental impacts can be considered priceless.
Additional information: Link to http://www.wsdot.wa.gov/partners/pns/default.htm