The captain did not verify that the tow tractor had exited the area in front of the airplane before taxiing for departure. Contributing factors were the dark conditions and the absence of an illuminated hazard beacon on the tow tractor, which reduced its conspicuity; the tow tractor operator’s positioning of the tractor too close to the airplane; the captain’s forgetting to verify the ramp agent’s display of the nosewheel bypass steering pin and provide him a return salute due to the performance of competing operational tasks; the flight crew’s rote performance of the “departure salute” checklist item and the required visual check of the sides of the airplane before commencing the taxi; and the ground crew’s discarding lighted wands during the pushback, which subsequently made it more difficult for them to attract the captain’s attention. In addition, the lack of procedure for ground crew to re-establish communications with the flight crew once the headset is disconnected from the airplane.