And recently, the shift has been helped by new state laws that encourage school districts to embrace new transportation models. A new Idaho law this year, for example, allows school districts to use smaller capacity vehicles to carry schoolchildren, not just yellow buses. “Buses are built to withstand collisions in ways no passenger vehicle can,” Curt Macysyn, executive director of the National School Transportation Association, told Stateline. Fewer yellow busesThe safest form of transportation to and from school is still the yellow bus, said Macysyn, of the National School Transportation Association. Private school bus contractors now account for 38% of the nation’s pupil transportation services, according to the National School Transportation Association.