It varies by region, but a lot of areas have a difficult shortage which results in really long routes or troubles when a bus breaks down/several drivers are out. Different states/areas also have different laws on when that means bus service just isn't available. There is, of course, a floor for the requirements of a driver, which drives these to get worse when salary (and therefore job interest) is lower.
Half a lifetime ago now, my bus route in high school took 1.5-2 hours to get me ~4 miles from the school after some route consolidations (I got stuck on the end of the combined route where they were about to return to the bus depot - depending on the year that meant either getting up really early or getting home really late). If the weather was good I could just bike it, but that certainly wasn't always the case in Michigan.
Half a lifetime ago now, my bus route in high school took 1.5-2 hours to get me ~4 miles from the school after some route consolidations (I got stuck on the end of the combined route where they were about to return to the bus depot - depending on the year that meant either getting up really early or getting home really late). If the weather was good I could just bike it, but that certainly wasn't always the case in Michigan.