Beginning at about noon today, for approximately three hours, crews from the City of Tucson Department of Transportation (TDOT) Streets and Traffic Maintenance Division will initiate Operation Freeze in preparation of freezing temperatures tonight. Operation Freeze is put into place to make sure City bridge decks are free of ice and safe for motorists to drive over.

During Operation Freeze, City crews will spray magnesium chloride on approximately 70 bridge decks within the City limits. Magnesium chloride lowers the freezing temperature of water and prevents ice from bonding on a roadway.  A light coating of magnesium chloride produces no negative effects on ground water, surface water or vegetation.  Magnesium chloride is an effective ice suppressant agent lasting for approximately 10 days. 

Motorists should to be aware of crews working around the bridge deck crossings and drive with caution.