Section 27.03 - General Restrictions(1) No motor vehicle operator shall cause or allow the engine of any motor vehicle operated by him or her on school grounds to idle unnecessarily, except under the conditions described in 540 CMR 27.04: Exemptions.(2) A motor vehicle operator shall not idle a motor vehicle within 100 feet from a known and active school air intake system, unless the school has determined that alternative locations block traffic, impair student safety or are not cost effective. Reasonable efforts should be made by schools to identify by signage all such known and active air intake systems.