Hi and

to disABILITIES!
The majority of attraction lines in WDW are "mainstreamed". This means that a wheelchair or
ECV will use the regular entrance and line all the way to either a show seating or ride load area. If a line is not mainstreamed there will be signs and/or Cast Members to direct you where to go.
If a show, normally there will be spaces to park a chair or ECV and there will be seats next to the space for other members of the group.
If a ride, usually you will have to transfer to a ride vehicle, although some rides will allow a person in a wheelchair to remain in their chair. If you have to transfer to a ride, and unload is not at the same location as load, your ECV will magically appear at the unload area.
However, be aware that some lines are
very long. For example, from the entrance to The Land to boarding Soarin' is over 1/4 mile. Also many of the exits are a long way from the entrances.