Anyone who falls under the category of road users, except pedestrians, is considered a driver.
A person who walks on the road with a bicycle, moped, motorcycle, or something like that, is regarded as a pedestrian. It, therefore, does not fall under the category of drivers.
Persons who move on a skateboard, roller skates, or similar are considered pedestrians. They do not, therefore, fall under the category of drivers.

A person walking on a road next to a horse is seen as a driver.
Someone who carries a cow on a rope is a driver.
A shepherd with a flock of sheep is a driver.

If the driver of a vehicle for the disabled drives on the sidewalk or footpath, or on a pedestrian crossing, that driver is considered a pedestrian.