Lunch times are a bit of grey area when it comes to telling them when to take one imho. I would think they would take one at about the same time everyday, depending on where they are on the route relative to a food stop. If they always seem to be on lunch break, follow them around (randomly) and stay out of sight so they dont know you are there. I know a ton of guys that will follow crews around to make sure they are not milking the clock.
Snow is another story, I would NEVER put the decision making process in the hands of crew leaders/drivers when it comes to snow, too much liability and responsibility to let them sleep in a bit or use their judgement. Set a time and make them adhere to it.
A handbook is a good idea if you are going to enforce ALL of it, once you let one aspect of the handbook slide it takes the teeth out of the remaining policies.
Why do you go out everyday for ice watch? Do you have a lot of melt and refreeze? do you get to charge for this service?