The desert of the Middle East is something like the Mojave, Sonoran and Chihuahua deserts of the American southwest - only without the trees and shrubs and grass. The desert is the place that Jacob entered after fleeing the wrath of his twin brother Esau. The desert is the place where the Israelites wandered after leaving Egypt. They wandered for a long time - whether or not it was 40 years, it was long enough for a generation to die off. And lest we think that the desert has been tamed over 3,000 years of Bible history, let me remind you that the Wilderness of Judah near the Jordan is where Bishop Pike, the famous radical theologian of the 1960's died.
People traveling in the desert have to be prepared for a rough time.
They will be hot, they will be hungry, they will be tired, they will throw away their possessions that have no use and above all, they will be thirsty. They will be tempted to give up hope. Some will die there. They challenged the people to prepare a road in the desert, to make it level, and broad, and smooth. Road building in the desert of the Middle East was not going to be easy.