A fourwheeler can be just as safe as or safer than a tractor if you don't hot dog it and use common sense. The secret is to get your wife on the four wheeler. Once she tries it she may find that she likes it. That is what I did and it worked for me! Trouble is, now my wife wants to move up a notch and get a Mule (of the four wheel variety of course!/w3tcompact/icons/smile.gif)
Guys it would be too funny to see my wife on a 4Wheeler. She doesn't even drive standard (not willing to teach either). But it has been a long time since I rode on an ATV, back when Honda only made the 3 wheel ones. That was long ago.