Bus Route/Seniority question for drivers

I have a question for you bus drivers out there.

How are your routes distributed? For example we have a new driver who just started this year because of a driver that quit...leaving a route open. If no other driver wants the open route, the new guy gets it...right? What if he doesn't? Can a lower seniority driver bump a higher driver out? What if route locations plays into this. The new guy lives in a different route (my route), and thinks to save the school $$ it would be best for him to have my route.

I'm not going to give my route up. I love most of my kids. What would your district do in a situation like this?