This varies from job to job and can only be addressed once we have examined your location. Factors that affect this are weather, pre-treated conditions of the surface, type of traffic, amout of traffic and direction of travel (ie: sharp turns, straight runs, etc.)
As a rule of thumb, campgrounds and private drives only need to be done once per year. Truck lots usually requre two or three applications per year. Grain elevators two per year. Heavy use factory lots: three to four per year. Scrap yards with tracked equipment: once every four to six weeks.