Salt may be applied only to the main streets, or only to bridges, hill stops, major intersections or slippery areas. Salt application rates are reduced on side streets. Also, a mix of liquid calcium chloride and rock salt is used when temperatures are at 25 degrees or below because it makes the salt more effective. Although the use of abrasives like sand instead of salt can be effective in rural areas and smaller communities, heavy traffic volumes in urban areas quickly pound down and bond untreated snow into hardpack that is extremely difficult to remove. It takes four to seven truckloads of abrasives to treat the same number of lane miles as a truckload of salt, and abrasives must be reapplied frequently.
Sand builds up in catch basins and sewers, necessitating expensive cleanup.
Sand does not provide the snow and ice melting capabilities of salt and liquid calcium chloride. Experimentation is underway in North America and Europe with other de-icers but the chemicals that perform comparably to salt are expensive. One of the most promising, calcium magnesium acetate, costs about 25 times as much as salt. Because of traffic volumes, performance and costs, most cities continue to use salt. Runoff into rivers and lakes is an environmental hazard.