In addition to metrolift, there a service for seniors and disabled called Harris County Rides. You put money on the account and they put additional funds. I put $20 on it and got an additional $30. And they use Uber if you fill out a form and you get a voucher loaded to your Uber account.
I'm not real familiar with these ride shares so thanks for asking the question. My question is, besides the metro because I know they do, do the rest of them load walkers and/or wheelchairs into the vehicle for the rider?