Situational Awareness
Conflict Ground Conflict; Critical
Human Factors
When Aircraft (AC) was ready to leave.  I was the push back operator.  Crew cleared me to push and wing walker gave me the all clear signal.  Commenced push.  During the push and after traveling ten feet.  Noticed a white 4x4 pickup moving at a fast speed on a path to pass behind the AC.  By the time I noticed this. The truck was already in my path of push.  I had to let off the gas immediately causing a jolt to the AC.  I then explained to the crew what had just happened.  When the truck cleared we recommenced the push.
During aircraft pushback; the tug operator noticed a pickup truck about to pass behind the aircraft and stopped the pushback.