Patrick Hall from Fstoppers recently did a short review of the Redrock Micro One Man Crew Motorized Parabolic Slider. This is an interesting unit which includes everything a single photographer/videographer needs in the field to do a movement video shot without any assistance.
The unit is pretty light (14 pounds/6.3KG) and has a length of 46″ (or 116cm). Its pretty easy to set up and use and it has a laser calibration which helps you stay in focus even while the camera is moving and getting closer or further from the subject.
The unit itself is relatively inexpensive (surly for a pro) and it can currently be purchased for just under $1500 (on B&H).