A convoy of camels  is a series of camels carrying passengers or goods on a regular or semi-regular service between point  Although they rarely travelled faster than the walking speed of a man  camels' ability to withstand harsh conditions made them ideal for communication and trade in the desert areas of North Africa and the Arabian Peninsula for centuries  though they could only travel on routes with sufficient sources of food and water  Camel trains were also used sparingly elsewhere around the globe but during the 20th centur   they have been largely replaced by motorized vehicles or air traffic