Odds of Hanging On
So, you'll be working with dangerous machinery and often in unfavorable (read: unforgiving) weather...that could be a turn off. But knowing that those are the conditions of the job, most people who are against them probably won't take the job to begin with.
Let's be honest, as a highway maintenance worker you're not exactly going to be rolling in it either. So fair warning: if you're looking for a frilly office job where you can sit indoors and make stacks on stacks of cash, you won't make it in this field.
The good news is that there are opportunities for advancement. After proving yourself as a worthy maintenance worker, you'll advance to operating the maintenance machines and then you can move up to lead a crew of workers (source). Dig in your heels, mop your brow, and work as hard as you can.