The first and most simple vehicle found in Rome, was the plaustrum. It was little more than a flat board carried by four wheels. The wheels were fixed to the axle in a stiff manner and the axle itself was also fabricated tightly to the cart. This made steering of the wagon a cumbersome business and meant a very low efficiency. These problems and the fact that no supple wagon had been invented to bind the animals in the front-only the Celts had invented a balanced harness to pull with-made freight over land costly and time-consuming.
The most impressive skill in Roman transportation was the so-called cursus publicus (something like ‘public race course’). This postal service was started by state couriers bringing information and diplomatic instructions into the far reaches of the empire. This developed relatively quickly into the organization of postal diligences that connected the various provinces with each other. These were not really public postal services as they were meant for people employed by the emperor and for the rich and powerful.
The cursus publicus was strictly regulated as far as size and capacity of its vehicles was concerned. Also it was precisely specified who was allowed to drive them, for what purpose and who was responsible for their maintenance. Because of the high cost of constructing and maintaining roads, transportation was managed in accordance with tight stipulations and great care was taken that a relative light maximum weight was allowed for the different modes of transport.
When the Roman empire lost its vitality, the cursus publicus became victim of nepotism and misuse. With the demise of Roman central power the excellent qualities of the system disappeared. Only in modern times the cursus publicus would be matched.
In general transportation was carried out by ancient customs. Sail boats were given a smooth skin, instead of riveting, and a fully developed keel with front and stern. The ancient Greeks used a square or oblong sail to catch the wind and in case of headwind they employed one or two rows of oarsmen to make headway. The Greeks were the first, as far as we know, to construct a special kind of battle ship with a ram at the front. Also they had freight ships without rowers and these, of course, were totally dependent on the wind. These developments were completed in the time of classical Greece. The Romans adopted both these forms without making any changes.
The Romans devoted much more attention to their roads than to transportation by sea. They worked out a remarkable network with carefully planned roads, both as far as the position as the construction were concerned. The road network was stretched out far and wide throughout all the provinces of the empire. Over these roads the legions marched to wherever there was a crisis. The roads also served for the development of trade, but their primary function always remained the maintenance of the imperial dominion.
At the zenith of Roman power trade was connected over land to the cultures of Europe, North Africa, Asia Minor and even China and India. But the system of transportation depended on the Roman, Chinese and Mauritanian empires. When these great powers collapsed, the trade routes became ways of invasion for foreign hostile armies. Almost everywhere the road networks became dilapidated for centuries. Freight transport was substituted by troupes of beasts of burden that were able to travel those ancient roads and that were sufficient to carry the lesser stream of goods. It would last till the twelfth century before the situation was improved.