In my area these turtles will hang out on roadsides to sun and lay their eggs. One day, I'm on my way home from work, and I almost rear-end a car stopped on a blind curve. The occupants were in the middle of the road, trying to coax a BIG mama snapper off the road with canoe paddles. I had to tell them that mamma will move on on her own, and all they're doing is making her hunker down.

Fortunately they took my advice and all parties were able to leave with their digits intact. I imagine mama moved on at some point too, once she calming down from being seriously pissed off by some tourists.