All of the following information is directly from Michigan.gov:
School buses are the safest mode of transportation for getting children back and forth to school. Riding in a school bus is safer than walking, riding a bicycle, or being driven to school in private vehicles.
Today's school buses are built with safety in mind. According to the National Highway Traffic Safety Administration, children are protected in large school buses by compartmentalization, a passive occupant protection system. This provides a protective envelope consisting of strong, closely-spaced seats that have energy-absorbing padded seat backs that help to distribute and reduce crash forces. Compartmentalization is most effective when occupants are fully seated within the bus seat. Seating should be provided that will allow each occupant to sit on a school bus seat without any part of his or her body extending into the aisle.
The majority of bus-related deaths and injuries involve pedestrians - mostly children - who are struck by a bus or injured when they are exiting the bus to cross traffic. Those who pass stopped school buses may be charged with civil infractions carrying a fine between $100 and $500. Violators may also be required to perform up to 100 hours of community service at a school.