Oh... I hate this question... here is the wording:
"Hunting with rifles, handguns, shotguns firing a single slug and archery equipment prohibited within 50 feet on each side of the center line of any public road."
So a shotgun with bird shot would not qualify in that. The thing is, I have asked several different DOW officers about this... some say you can fire as long as you are off the road itself (but not across it of course) Others say that the 50 feet rule applies to shotguns with bird shot as well.
I have hunted some ditches without being 50 feet away... especially during dove season. That said... I move further out if I see a truck coming, just in case.