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BAY COUNTY ROAD COMMISSION
SNOW REMOVAL-ICE CONTROL
Snow removal and ice control are no doubt one
of the most demanding tasks any highway maintenance
agency has to deal with. You do the best you can
with what you have and hope the complaints will
be minimal.  Maybe
you will be complimented, but don't bet on it.
It's far easier for the public to respond to poor
road conditions than to say "Thank you for
the clear roads."
Winter weather and the related storms are far
too complex and unpredictable to have a simple
set of rules or policies. Mother Nature does not
always co-operate. It has been estimated that
there are over 66,000 different winter storm conditions.
Each storm requires its own analysis and resulting
response. Our goal is to provide safe roads for
the public as quickly and efficiently as possible.
Winter maintenance includes the snowplowing
and deicing of the road surface. The most effective
and least expensive deicing material available
today is sodium chloride, or rock salt. To understand
why, where, and when to apply rock salt, we must
understand how it works. Salt, used as a chemical
deicer, must dissolve on the road to be effective.
Once applied to the road, salt uses moisture from
ice or snow on the road surface to dissolve and
form brine. Salt - as it dissolves - gives off
heat, melting the surrounding snow/ice and continues
to form more brine. The dissolved salt lowers
the freezing point of the surrounding water and
prevents refreezing. Heat from sunshine, rising
daytime temperatures, and heavy traffic volume
help maintain this melting process.
Once the brine has formed, it works its way
through the ice/snow down to the pavement surface.
Gravity then spreads the brine from the crown
of the roadway toward the shoulder, breaking the
bond of ice/snow. This, of course, takes time
and we must wait for the salt to do its work.
The melting action starts quickest at temperatures
above twenty degrees Fahrenheit, and will continue
working for about three hours. At temperatures
below twenty degrees, an effective treatment can
still be made by adding calcium chloride to salt.
Salting operations typically start when snow
starts to adhere to and accumulate on the driving
surface, or when the road becomes slippery. Winter
driving requires extra caution on hills, curves,
bridge decks, and intersections. When plowing/salting,
it is desirable to crowd the centerline of the
road and move the snow to the outside edge. Deicing
materials are applied near the crown or centerline.
Studies show that snow melts faster when salt
is applied in narrow (three or four feet) strips.
To help keep the salt from bounding onto the shoulders
or off the road, the truck speed should never
exceed 35 m.p.h. Experience has shown that by
keeping the salt centered in a narrow strip, the
brine will form quicker and flow from the crown
toward the outside edge, breaking the snow/ice
bond.
Weather conditions have a major influence on
salt application and snow removal. Predicted weather,
temperatures, current conditions, wind direction,
wind speed, and traffic volumes, all influence
what type of treatment should be initiated. Spreading
salt in windy conditions requires a lot of forethought.
Wind not only affects salt patterns; it affects
the salt brine as well. During extreme windy conditions,
brine may not form or flow like it normally would.
There are times during heavy winds when snow is
blowing across the road that salt should not be
applied at all. The application of salt at this
point may worsen conditions.
During the winter months, the Bay County Road
Commission (BCRC) utilizes a 24 hour-seven day
a week road patrol for monitoring weather and
related problems. These patrol people provide
for a positive and quick response by BCRC, should
conditions dictate. The Road Commission will respond
in force when conditions warrant it. The State
Highway system is the first to be plowed. As soon
as the State Highways (I-75, US10, M-15, M-25,
M-247, M-138, and M-13) have been plowed and treated,
the trucks go to the county primary road system
(Midland, Wheeler, Beaver, Mackinaw, Seven Mile,
Wilder, etc.) which is then plowed and treated.
Under normal conditions, it takes about four hours
to clean up the State Highway system. When the
primary system is done, the trucks go on the local
road system and subdivisions. Years past, it would
take over a week to clean up after a snowstorm.
With the new trucks and equipment, trained manpower,
and new techniques, a typical storm can be cleaned
up in two days. |
