When talking salary and transit, it should be noted that the US does not have any living wage laws, only a federal minimum wage.
Minimum wage in most "1st world" countries is about 13-14 us dollars per hour.
The problem is not high transport wages, the problem is low minimum wage not tacked to cost of living index or inflation, and other wages and prices being affected by health insurance and other such costs.
Being a bus driver does come with dangers, and it is a very demanding job physical and/or mentally, as are most transportation jobs.
There's a lot more to all this but not going to get into it here. Generally things here in the US are very out of balance and the riding public often pays for it, which often further causes problems.
Next stop the square, journal square station next!