I think those people should be required to have flags, reflective material and bright blinking lights so we can see them during the day and especially at night.
Hell, I’d even be willing to subsidize them with a .000001% tax to install them.
(can’t believe I actually agreed to that but there it is. They really bug me that go out and expect us to see them. They are below eyesight and many times I thought they were a Mailbox)
I've never seen any visibility aids of any kind on a wheelchair.