How this came to be is written up in an article http://www.saudiaramcoworld.com/issue/198104/the.nairn.way.htm in which the Nairn brothers found a need and filled it with a bus route between Damascus and Baghdad, cutting the route in 1/3rd the previous standard time.
90 percent of the travelers used Nairn... it was a dangerous time, natives were hostile, water was no where around, and few vehicles could make it. Nairn charged the equivalent of $50.
The Nairn brothers stayed in the Syrian area after World War 1, and realized that the overland route had been unused since Vasco De Gama figured the way around the southern tip of Africa. So the brothers took a plow and made a trail between the Mediterranean and the Persian Gulf. The plow didn't create the trail... the plow was in case they got lost, they could then follow the furrow back to civilization