The consolidation of the post towns on the five main highways, and on the other roads designated. by the Tokugawa government, was originally for the supply of men and horses for official needs, chiefly for the going up to and coming down from Edo for the alternate-year residence of daimyos
. In using the regularly stationed men and horses at these post towns, official needs were first met on priority basis and the transportation of common travellers and merchants' goods and luggage was always deferred. The chief duty of post towns was to offer men and horses for official traffic, which was indeed a heavy burden to these towns. Although taxation on the lands they lived on was exempted in compensation for the expense and service, it was not sufficient to make up for the loss. Therefore, these towns were permitted to cover it by gaining profit offering service for common travellers and carrying merchandise in their leisure hours, or by obtaining the license of keeping inns and shops in the towns.
The profit thus gained by transporting goods and luggage of common travellers was very importan_??_ to maintain the functions of post towns. But private travellers and goods were not only deferred in transport but were transshipped at every post town. And this transsipment had such shortcomings as damage in the goods, delay in the time of transport, and more cost in carriage and commission. It was only too natural, therefore, that merchandise in general tried to avoid being forwarded in this relay system; they would have avoided if they had been able to. But the system was protected and carried out by the authority of the government; the five main highways and the other roads designated by the government were privileged traffic routes located with the strong governmental protection at their back.
The inconveniences of these routes were not keenly felt in the earlier stages of the Edo government, when traffic was not so dense and transport of merchandise was small. Besides, the authority of the government made it impossible for people to resist. But as more merchandise came to be transferred and more people began to travel, the inconveniences and conflict of interests became more and more apparent. By and by there appeared gradually an indication that people would try to avoid the privileged routes. In addition, the gradual loosening of the government in the enforcement of laws and regulations accelerated the tendency. Consequently, there arose a new means of transport contrived by private transport agencies to forward merchandise through by carriers using horses or oxen. These carriers and horses (or oxen) sometimes avoided certain post towns on the way; mostly they tried to utilize only the byways if available.
Thus the new means of transport was born by the need of cheap and puick way of forwarding goods, while the old privileged routes had the protection of the government or feudal lords in their background. As the traffic on the byways prosperd, more goods came to be sent by them and the main highways wera more neglected, which was a vital problem to post towns since their functions must be paralyzed in the end. The two were destined to conflict and the power of the government was another factor to complicate the matter. This made a characteristic feature of the traffic system in the Edo period, especially in its middle and later stages. Whether one liked it or not, the situation turned favorable on the byways and the traffic on them became more and more heavy while it became impossible in the end to maintain the post-town system.
The Present study has chosen a certain area with the Usui Pass in its center where byways developed most remarkably and using litigious document and maps of villages preserved in places which used to be post towns, has considered the relation between the post towns and the byway traffic.