Each vehicle working the current shift has an icon placed in the column describing the unit's current status. A log book is used to track times, event details, and other information about calls for service. In a tow truck example, the icon might be labelled with the tow car's radio identifier, "Down town 6". During a shift, the icon would be moved by the dispatcher into whatever column describes the resource's current condition. Alternatively, there could be columns for some other condition such as the names of move-up or standby points where resources are sent to backfill for busy tow cars.