Typically, and I think this is true of the Tower, the CM at load simply pushes a button when their load station is "ready". That signals the master ride control computer that Lift Alpha (for example) has a guest on every number and that they're ready for the safety spiel. Once the computer knows that an AGV is so many seconds away from being ready to load, it triggers the safety spiel, rotates the faux Floor Dial from 13 to 1 (to imply the elevator is coming down to get you from the 13th floor), and then opens the doors when the vehicle is in place. So, if a group of riders is queued up pretty quickly on their numbers, the CM may hit the "Ready" button and it may take a while before anything starts, since your vehicle may still be backing away from Unload, right below your feet. On the flip side, if your group takes forever to assemble, the CM may hit the Ready button and the safety spiel start right away. Sometimes, the doors open while the spiel is going, if the delays are causing a log jam. In those cases, the lift was likely sitting behind the doors already. Once loaded and seatbelts have been confirmed, CM will hit a "Ready to Dispatch" button. Again, all that does is tell the computer that it can take this vehicle, when the system is ready for it. Sometimes you'll go immediately, other times there might be a slight delay, while it allows the previous vehicle to get far enough ahead to clear a safe path. Other buttons will manually start a safety spiel, or some other pre-recorded spiel. Some signal the control tower. Some is a microphone control so the CM can make his/her own spiel or announcement. Another is likely a KILL switch. One might manually open the doors. Then, a variety of indicator lights tell them things, like when a vehicle is nearing load, or if it's ready to dispatch. A good CM can glance at the console and know what's going on instantly. He'll know how long until his vehicle arrives, so he can pace his queuing accordingly, thus resulting in a seamless process for the guests.