The intent of salting first is to ensure that a brine layer forms, which minimizes the amount of ice that accumulated on the streets. We almost without fail salt all the streets first to ensure the brine layer is in place.
To salt it takes anywhere from five to seven hours depending on road and traffic conditions. We almost always complete the salting before plow operations begin. Additionally, the city utilizes trucks that both apply salt and plow, so it would be impossible in most instances to do both at the same time.