An accessible walk right in the heart of Edinburgh, with pretty views across the City.
I would think that the route is fully accessible to all, no matter what equipment you use. There are also plenty of benches if you need to take a rest every so often.
A big disappointment is that there is no public accessible toilet.
The carpark is a stones-throw from the Scottish Parliament and the Dynamic Earth museum which I'm sure will have suitable toilets.
Below is a short clip showing the beginning of the route.