WINTER MAINTENANCE STUDY WITHOUT THAWING AGENTS IN THE CANTON OF ZURICH

THIS SHORT REPORT DEALS WITH THE RESULTS OF A FIVE YEAR STUDY. FROM THIS IT APPEARS THAT WINTER MAINTENANCE WITHOUT DEICING SALT IS TWO TO THREE TIMES DEARER THAN WITH SALT. THE SKIDDING RESISTANCE OF THE PAVEMENTS COVERED WITH SNOW OR ICE, WITHOUT DEICING SALT (75% OF THE TIME) IS INADEQUATE IN SPITE OF SPREADING OF CHIPPINGS. IN THE CASE OF ROADS SPREAD WITH SALTS, THE SODIUM CHLORIDE CONTENT IN THE MELT-WATER REMAINS AT 1.5 TO 3.5 G/L, WELL UNDER THE LIMIT PERMISSIBLE FOR FISH LIFE (7 TO 20 G/L). SODIUM CHLORIDE IN THE SOIL DROPS IN THE SUMMER TIME; PLANT DAMAGE IS NOT ESTABLISHED. SURVEILLANCE AND LIMITATION OF THE SALT USE IS RECOMMENDED. THE SPREADING OF SALT MAY BE DISPENSED WITH ONLY IN LEVEL AREAS AND ON SIDE STREETS CARRYING LITTLE TRAFFIC.