Really? Wide open? I had no idea...
Yeah, most construction equipment has a throttle lever (fancy newer stuff has a dial or push button control) and you either set it to 100% or an idle. Full throttle gives you maximum power in your hydraulic system, and machine travel speed is controlled via a hydraulic valve, variable geometry pump, or hydrostatic transmission.
So when a machine's being used in production work, and the operator isn't constantly getting on and off the machine, or waiting on trucks, or the like, it's running wide open until it's time for a break or you have stop for fuel (or water, depending on what the machine is).
