On or before July 1, 2007, the department shall adopt rules governing diesel engine idling to restrict the unnecessary operation of non-road diesel engines. So far as is reasonably feasible, the rules shall provide that no entity shall cause, suffer, allow or permit the unnecessary idling of a non-road diesel engine. Non-road diesel engines to be considered in this rulemaking shall include, but may not be limited to, construction engines, airport ground support equipment, commercial and industrial equipment. Unnecessary idling shall not include such periods and circumstances as the department may determine as reasonably requiring that the engine remain idling, which periods may include, but not be limited to, when airfield maintenance vehicles are being used on a state-owned or operated airport. This provision shall not extend to any diesel powered engine and/or vehicle that must continuously operate while stationary in order to function properly, a vehicle making deliveries of fuel or energy products, or to insure workplace safety.