Certainly it is a plus to have such a resource - and by all means, use it.
But I think the best comment about determining whether Mom should continue to drive came from one of my Community Relations Directors. Now, this lady has seen the elephant; she has vast experience, states her truth plainly ... and is a delight to be with, to boot.
She says, "YOU have to be the objective evaluator. You have to take yourself - and your family member - out of the picture. You have to look dispassionately and determine: 'Is it safe for this individual to drive? Would you want to be driving on the same street as this individual?' And then you have to have the fortitude - perhaps spiced by savvy, perhaps not - to implement that decision.
This logic applies to so much in this emotionally charged arena of caring for a parent. Easy? No. Simple. Not easy.
By all means, use all the resources at your disposal: Third party evaluators, State License Bureaus, friends, clergy ... But, in the end, it's you.
You know. So take the necessary steps, whichever way you determine. And save both you and them the worry ... and possibly the guilt over something that could have been avoided. Take the steps to keep them - and others - safe.