The School bus driver 'physicals' are a joke, and I think they should have to pass an 'agility' test. In the event of an emergency, there are quite a few drivers out there that could not evacuate children fast enough to prevent fatalities. Discrimination? No. It's all about being physically able to do your job.
someone that large cannot use a shoulder belt without a seat belt extender. as for ability to do her job, size can be deceiving, I know many large people who are more agile than skinny people