Porters, jungle track. These tracks were originally constructed as bridle-roads for military mule-transport they were, apart from the very precipitous native paths, the only means of communication at that time in the hill areas. During World War II many of them were improved to take jeeps and even heavier vehicles, but as they were earth-surfaced, they became almost or wholly impassable during the monsoon there are many references to this in books covering operations on this front in 1944. It was a major factor.