At the ILC where I worked, we had a van for some years that we used to transport people with disabilities to doctor's appointments. It had a ramp though, and because of that we would only transport wheelchair users. We only had the one van, and we figured that if you could ride in any other kind of vehicle, you had more options. We reserved our service with people who had no other options. At the time I actually rather hated this policy, too, since we had to turn away people who didn't have their own cars, didn't have friends or family to drive them, or couldn't afford cabs. But at least the policy made some sort of sense for a disability organization.
There's a "Change.org" petition to sign:
"Currently, the jointly operated DAV-VA National Transportation Program offers free rides to Veterans needing transportation to Veterans Administration Medical facilities. Most of the vans are not wheelchair accessible leaving out the most (physically) disabled Veterans who use wheelchairs for mobility. In addition, there are written policies in place stating: "ambulatory only/no wheelchairs". This policy is discriminatory and must be changed."