In Massachusetts, it is illegal to pass "When approaching a vehicle which displays a sign bearing the words “SCHOOL BUS” and which is equipped with front and rear alternating flashing red signal lamps which are flashing". There is a minimum of a $250 fine for any violation. Repeat offenders can be fined up to $2000 and have their license suspended.
If a school bus or a school pupil transport vehicle has its red lights flashing and a stop sign extended, you must come to a complete stop. It is the law. It does not matter which side of the road you are traveling on. Remain stopped until the lights stop flashing or the stop sign folds back. The only exception to this law is if a school bus has stopped on the other side of a divided highway with a solid barrier between travel directions. In this case, you do not have to stop.
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