(a) Notwithstanding the provisions of subsections (a) to (c), inclusive, of § 14-242, the operator of any school bus, when about to bring his bus to a stop to receive or discharge passengers, shall signal his intention to do so by causing the flashing signal lights to be displayed for not less than fifty feet before he brings the bus to a stop so as to be clearly visible to the operator of any oncoming or overtaking vehicle or motor vehicle, except that the operator of any school bus equipped with amber flashing signal lights shall signal such intention by causing the amber flashing signal lights to be displayed for not less than one hundred feet before he brings the bus to a stop. The operator of any school bus, having brought his vehicle to a stop, shall not open the door to receive or discharge passengers until all vehicles approaching from the front and overtaking from the rear have stopped in compliance with the indicated signal to stop. The operator of any school bus equipped with amber flashing signal lights and a stop semaphore, having brought his vehicle to a stop, shall cause the red flashing signal lights to be displayed and the stop semaphore to be extended and shall not open the door until all vehicles approaching from the front and overtaking from the rear have stopped in compliance with the indicated signal to stop. After all passengers are safely aboard or discharged and safely off the highway, the operator shall extinguish the stop lights and the operator of any school bus equipped with a stop semaphore shall withdraw the stop semaphore. He may then permit all standing traffic to pass before resuming forward progress. While such school bus is in motion the doors shall remain closed at all times and all passengers shall be required to remain seated. No operator of any school bus shall stop his vehicle on the main traveled portion of the highway to receive or discharge passengers when existing highway shoulders or adequate highway width is available or where curbs, bus stops or special facilities exist. No such operator may receive or discharge any passenger on a highway with separate roadways unless (1) a boarding passenger may reach the bus stop and a discharged passenger may reach his residence or other destination without crossing such highway, or (2) he stops the bus at a location having a traffic control signal or crossing guard.

(b) The operator of any school bus shall not operate the engine of any school bus for more than three consecutive minutes when the school bus is not in motion except (1) when the school bus is forced to remain motionless because of traffic conditions or mechanical difficulties over which the operator has no control, (2) when it is necessary to operate heating, cooling or auxiliary equipment installed on the school bus when such equipment is necessary to accomplish the intended use of the school bus, including, but not limited to, the operation of safety equipment, (3) when the outdoor temperature is below twenty degrees Fahrenheit, (4) when it is necessary to maintain a safe temperature for students with special needs, (5) when the school bus is being repaired, or (6) when the operator is in the process of receiving or discharging passengers on a public highway or public road.

(c) Any person who violates any provision of this section shall, for a first offense, be deemed to have committed an infraction and for each subsequent offense shall be fined not less than one hundred dollars nor more than five hundred dollars.