A slightly older article posted ion the KI site originally reported from Agence Presse in Vietnam. Apparently it's not all small-timers involved in the smuggling of fuel:
Crossing Cambodia
Crossing Cambodia seeks to reveal the intricacies of traffic related issues both to those living in Cambodia and those outside. This is done by informing readers of the current status of travel in Cambodia, current traffic related issues and essays on the background of how and why traffic conditions evolve as they do in Cambodia.