Maybe a higher luck?
Mine's 7 and I rarely get stopped in random encounters on F2...
I have 4, 5 or 6, I don't know, but I don't feel like starting over...
Encounters are linked to your outdoorsman skill, the official way to reduce these is to increase this and the pop-up will appear more often giving the the option to avoid.
The car will let you travel further between encounters
There is a setting that can be tweaked to reduce the encounter rate if you've installed either of Killap's patches.
Thanks, I think mine is around 50 thanks to some books, but I guess I'll raise it soon. I haven't been given the option since the beginning of the game though.