After a few mild winters, this season has seen many winter storms, causing an increase in the amount of road treatment materials and related costs to maintain Pennsylvania highways.

Marla Fannin, spokeswoman for District 2 of the Pennsylvania Department of Transportation (PennDOT), which includes Centre County, said PennDOT has been going through a large amount of road salt and other materials used to prevent slippery highway conditions.

"We are moving through it at a pretty good clip," Fannin said.

She said despite the increase in material use and the subsequent cost, roadways throughout the state will continue to be treated throughout the winter, even if totals go over budget.

"We will continue to purchase material to keep the roads clear," Fannin said. However, the trade-off could be a decrease in summer projects such as fixing potholes and doing other roadwork, Fannin said.

The State College Borough is nearly on target in regard to expenses from snow removal, said Mark Whitfield, director of public works.

But he also said so far this winter, expenses are far above what they have been during the past few winters.

Total labor expenses in 2002 were about $20,000 before December, Whitfield said, but jumped to $33,000 by the end of the year.

"We're blown away," Whitfield said, who added that despite the appearance of heavy snowfall this winter, the numbers are actually about average.

An average winter in State College is characterized by about 42 inches of snow and about 19 calls for road crews, he said. This winter seems to be bad because many mild winters have spoiled people who now have to deal with the weather, Whitfield said.

Plow trucks in Centre County normally apply a mixture of salt and limestone gravel to roadways, said Ronald Chubb, PennDOT county manager. Chubb said limestone is used because it is cheap and readily available in this part of the state. In other areas, other types of gravel, such as sand are used, he added. Many factors go into how treatment materials are mixed and applied, Chubb said.

When temperatures are at or near 32 degrees, salt is applied to area highways. However, as the temperature drops, limestone is added in increasing amounts to act as an anti-skid material to help vehicles maintain traction on slippery roads, Chubb said.

Salt brine is also commonly applied to roadways before winter precipitation, Chubb said. He also said the salt and water mixture is sprayed onto salt and limestone mixtures as they are applied to road surfaces to help them stick better.

These materials can cause damage to both automobiles and roadways because of their corrosive nature, but it is hard to gauge how much damage is done, Fannin said.

In some parts of the state, newer materials are being used, but not in Centre County.

One new material, magnesium chloride, is being used in parts of Dauphin County. Magnesium chloride has a freezing threshold of about minus 10 degrees, and is also less corrosive than salt, Fannin said.