Power Take-Off (PTO)
A mechanism that takes power from the engine or transmission to drive mounted equipment. The reason so much public fleet equipment must run with the engine on.
A power take-off drives something other than the wheels: a dump body, a packer, an aerial device, a pump, a spreader. The engine runs while the vehicle is stationary because the engine is what powers the work.
This is the single most common reason a public fleet cannot simply apply an idle reduction policy, and why idle data has to distinguish PTO operation from a vehicle sitting with nobody in it. Treating the two as one number produces a target the crews correctly ignore.
It is also one of the harder problems in electrification, since a PTO duty cycle draws real energy from the same battery that has to move the vehicle, and the two demands compete.
