It is illegal for kids (especially Ralphie/"Weatherman") to drive or operate the Bus, letalone any other motor vehicle. Driving a school bus requires a Class B commercial driver's license and must be at least 18 years old to earn this kind of license to drive or operate such vehicles.
Phoebe mentions in this episode that her old school used the metric system, implying that her old school is in Canada. But in the earlier episode "Goes to Seed" where her old school is shown, her former teacher Mr. Seedplot rides his bike presumably about five miles to Walkerville Elementary School that is clearly located in the United States.