For my dad's safety! - vertigo while driving

[chrysostom]

My dad, who lives in a different state, drives an hour/hour and a half to work every day. Recently he's been having sudden bouts of vertigo. He told me that it's happened while he's on the freeway before, and the only way he can make it through those is to keep driving straight, use the mirrors, and not turn his head anywhere so as not to throw off his balance, until he feels okay again. I'm really incredibly worried he'll get in an accident.