It is imperative you find a social worker who specializes in geriatrics as soon as possible. It sounds from your question as if your mother does not need a nursing geriatric social worker can evaluate her and help you know for sure. Even if she still refuses to move, a geriatric social worker can help you gain a better understanding of the situation and what the options are.
home but an assisted living community; a
You haven't mentioned if your mother's mental state has been evaluated by a doctor, or if you have discussed the problem with a professional. Sometimes "disruptiveness" is due to early stage dementia or depression, so you should have your mother evaluated for this as well.
Don't wait too long to find a social worker. You could call the Family Care Alliance and ask for a referral, or your local Area Agency on Aging.
If your mother truly is a danger on the road, you may also need to go to the DMV and discuss the situation with them as well.