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 organized.
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 expectations.
"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."
