Idling school bus engines

The subject of idling diesel engines is froth with superstition and misinformation, a hold over from a time when greenhouse gases and high diesel prices were not issues. The move towards green thinking is however having an impact on what has for years been standard practice. It used to be OK for trucks/buses to sit and idle their engines for extended periods of time. Often times without justification. Today, it is unlawful in several states to idle buses for over three minutes except in certain instances. Obviously we are on the way to modifying our habits. During warm weather I have generally refrained from automatically starting my bus engine before the pre-trip inspections, opting instead to turn the ignition to acc. which allows lights and safety devices to operate as needed. While it may be necessary to let the bus engine warm up in cold weather, it is not necessary when warm weather is upon us. It’s just my small contribution to cutting down on carbon laden exhaust emissions.