Trial Runs

Indianapolis treats its streets with treated salt

April 16, 2003

When the snow starts to fly--and it always does--the
residents of Indianapolis still need to go about their daily routine regardless
of the conditions. Ice, snow and sleet bringing the city to a standstill is
simply not an option. And the assumption made by the public that the roads will
be clear when they head out is not taken lightly by the men and women of the
Street Maintenance Division of the city of Indianapolis.

As part of the Street Maintenance Division for the
Department of Public Works, Steve Pruitt, assistant administrator of operations
for the city of Indianapolis, and Mike Dale, manager of the Martin Luther King
Garage, are responsible for the safety of thousands of drivers throughout
Indianapolis. The mission of the Street Maintenance Division is clear: to
provide safe streets through efficient and timely snow and ice control. This is
to be accomplished by being properly equipped, properly staffed and well

And it is not just in winter when snow and ice control is
top of mind for the department. As fall approaches, the fleet of 130 city
vehicles is put through maintenance checks and comprehensive inspections in
order to be ready when the first storm of the year hits. And the drivers are
ready when the flakes begin to fall, because they will have completed a
refresher course on proper handling of vehicles and safe winter driving
tactics. The seven salt garages around the city prepare by housing more than
18,000 tons of salt. The city also has a separate 10,000-ton stockpile to
ensure an adequate supply.

Based on the most up-to-date weather information, the Street
Maintenance Division determines the need for preventive action. If a storm is
heading their way, crews are put on alert and schedules are set to help tackle
the incoming precipitation. The intensity of the storm helps determine the
frequency with which the more than 375 predetermined snow routes will be plowed
and treated.

Once on the road, the city's plows use several anti-icing
practices to help prevent the ice and snow from freezing to the pavement.
Salting is the most common way to tackle the problem. However, one of the
mixtures that the Street Maintenance Division uses is far from the ordinary.

Winter tryouts

Starting in the winter of 2001, Indianapolis started using
ClearLane treated salt from Cargill Deicing Technology. ClearLane is a treated
deicing salt that combines the ice-melting power of magnesium chloride with
cane molasses, which gives the product a distinct brown color. The cane
molasses helps the product stick better to the pavement, minimizing scatter and
waste while also reducing corrosion on snowplowing equipment. ClearLane also is
designed to be more environmentally friendly than regular salt.

After hearing about the product, the Street Maintenance
Division decided in 2001 to try ClearLane on an area 60 blocks wide from north
to south and including the downtown west to the county line, a distance
equivalent to 12,000 blocks. The results of the test usage were beyond anyone's

"The ClearLane was used for pre-treating and regular
deicing," said Pruitt. "The ClearLane spread real evenly, and there
were no clumps whatsoever. In fact, we were even able to set our gates at a 1/2
in. versus the usual 1 to 11/2 in. It dropped to the road and adhered right to
the pavement, just like it was supposed to. Regular salt often clumps up after
a while, but with ClearLane we had no frozen loads. That tells you what the
product will do. It also left behind a residual that was effective when we had
one wave of snow after another."

"This eliminated a safety hazard as well," Dale
added. "With regular salt, we sometimes get 'hitchhikers,' the clumps of
salt that can plug up the gates and prevent the salt from draining. With
hitchhikers, we would need to send someone up to clear the salt, and that is
always potentially dangerous. With ClearLane, we had no clumps, so we did not
have to send anyone up."

The Department of Public Works also received unsolicited
feedback from the general public and media. People wanted to know why the
streets of downtown were so clear. Residents even claimed they could see where
the test area started and stopped.

As well as showing results in the field, some transportation
departments using the product have claimed cost savings--important given the
tight budgets that most transportation departments around the country face.

"We used one-third less product," Pruitt said.
"In certain critical areas where we would normally have to reload the
trucks, we were able to make it through in one pass with ClearLane."

Nonscattering salt

Environmental issues are another area of concern for
transportation departments. With a greater focus on causing less harm to the
environment, the tide might be turning toward using deicing salts that are
effective but have minimal environmental impact. Runoff and damage to
vegetation are just two of the many concerns.

One reason ClearLane is environmentally friendly is that
more of it stays where it should--on the highway. When applying untreated salt,
only 49% of the product stays within 12 in. of where it hits the pavement.
Inevitably, more than half of untreated salt scatters, increasing its chances
of landing on roadside vegetation. With ClearLane, nearly 80% of the salt stays
within 12 in. of where it hits the pavement, minimizing its contact with
roadside vegetation.

As for Indianapolis, Pruitt was pleased with what he saw in
the spring of 2002. "We now can also see that it was environmentally
friendly. In areas where regular salt could damage grass, the grass is OK where
we used ClearLane," said Pruitt.

"Storage was another issue for us," Dale added.
"The Martin Luther King Garage is in an area that is a major concern for
environmentalists. We had zero leeching unlike what we had with regular salt.
It did not run and cause puddles when stored."

Going into the winter of 2003, the city of Indianapolis
substantially increased its ClearLane order. As of early February, Indianapolis
had received over 25 in. of snow.

"We are now using it on the north side, two-thirds of
the west side and in all of downtown," said Pruitt. "All my drivers
love it. As a matter of fact, we are looking at buying nothing but ClearLane in
the years to come."

About the Author

Information for this article provided by Cargill Deicing Technology, Minneapolis.

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