human
You all wait here with the cabs. Shut off your engines. I'll go ahead and look over the ground. If I have to stay on watch I'll take cover in that clump of bushes opposite the entrance. Keep your eye on me. If I want you in a hurry I'll signal with my pocket flash. One flash, start your engines; two flashes move your cars up; three flashes shut your engines off; four flashes come on foot on the run.