"Consumer Ratings" of Senior Transportation Companies?

[Mike7SoCal]

My elderly mother is looking at services that provide transportation for seniors to appointments.  How does one "vet" these services to make sure they have good ratings (reliable, dependable, etc.)?  I've found plenty of good reviews on Google, but I am looking for more candid reviews, similar to Yelp reviews of restaurants.  Is there a site that provides ratings of these service firms?

[GailL1]

This list lots of different kinds 

AARP 01/17/2020 Transportation: What Caregivers Need to Know

If you use an agency and before signing on ask how they check out their drivers.  There is one around my area that is called GoGoGrandparent.  Their catchy name is about all I know about them, but their website shows many high hitter endorsements, or rather they are listed - you be the judge.  I did not see any place where AARP actually endorsed them.  I think most of these services use Lyft and Uber - so how does anybody really check them out.

GOGOGRANDPARENT.com

If it is medical transport - some Medicare Advantage plans and some Direct Contracting Medicare Entities have transport to medical appointments as a benefit.