The queue for VelociCoaster is wide enough to accommodate both manual and electric wheelchairs. Once you have put your belongings in the locker, you will be asked your name and asked to wait in the child swap area.
When it's your turn to ride, a park employee will call your name and take you to the elevator that will take you, in your mobility device, to the coaster platform. One on the platform, they have an area where you're able to leave the wheelchair and transfer into the coaster seat if you can walk. If you need assistance, let the attendants know and they will bring a device to help you transfer!