<論説>律令期の伝馬制と交通路体系について : 「伝路」概念の再検討を通じて

Abstract

近年、郡家間交通路を伝馬制等と結びつけて「伝路」と呼称し、律令期における交通路体系が駅路と「伝路」により構成されていたとする見方がある。しかし、伝馬や伝使は、郡家間の交通路上のみを往来していたのではなく、郡内外のさまざまな道路上を往来しえたと考えられる。このことは、通行が駅路上に限定される駅馬と大きく異なる点である。したがって、郡家間交通路のみを「伝路」と呼び、あたかも駅路と対比される交通路体系が存在していたかのように理解することは妥当でない。伝馬は駅路を含むあらゆる地方交通路での利用が想定されており、伝馬制は、駅制のみではカバーすることのできない律令国家の中央―地方間交通を補完する制度と位置づけることができる。

In ancient Japan, there were two traffic systems, the eki 駅 system and tenma 伝馬 system. In the tenma system, five horses called tenma, were stationed in each county 郡, and were provided to messengers called denshi 伝使. Recently, it has come to be supposed that there existed roads for the tenma horses and denshi messengers, and that these roads were called denro 伝路. More specifically, the roads linking every government office within a county, called guuke 郡家, on which the tenma and denshi traveled, have come to be considered denro. In short, it is supposed that the road system in ancient Japan was composed of two major systems, called ekiro 駅路 and denro. However, several problems arise if the roads that linked the guuke are termed denro. Firstly, it assumes that tenma horses were stationed only in counties that had ekiro. Secondly, it assumes that there were denshi messengers who traveled to and from the guuke without employing tenma horses. Thirdly, it assumes other tenma horses were stationed only at the guuke and that the denshi messengers always traveled to and from the guuke offices. And fourthly, it assumes other functions of the county related to traffic, such as providing meals for travellers and conveying official documents among the various guuke offices, can be subsumed within the concept of den 伝, and it also supposes that the tenma system was a part of the den. Examining historical records and the relationship of the guuke offices and the location of ancient roads, the following facts have come to light. (1) In relation to the first problem noted above, tenma horses were stationed in all counties, including those that did not contain ekiro. (2) As regards the second problem, it is clear that in general denshi were never free to come and go among the guuke without employing the tenma horses. (3) It is very probable that denshi messengers were provided meals and tenma horses by other facilities in addition to the guuke offices. (4) In no instance was the word den used for the broad traffic functions of a county in historical records. It is highly probable that denshi messengers, who in principle left the capital for the provinces on tenma horses, traveled along the ekiro in order to take the shortest possible route to their destinations. On the other hand, it is also probable that they may have traveled on any road in the county on tenma horses, depending on their purposes. This point distinguishes the system from that of the eki, in which ekiba 駅馬 were limited to traveling only on the ekiro. In concluding, it is inappropriate to call the roads linking the guuke offices denro and to assume there existed a separate highway system besides the ekiro. The tenma system differed from the eki system in that no special roads were prepared for the tenma horses, and the horses could travel on any local road, including the ekiro. In this sense, the tenma system can be regarded as a system designed to complete the traffic system by linking the capital and the provinces, which the eki system could not cover. The tenma system was abolished at the end of the eighth century, and revived in the ninth century. But, in this later stage, tenma horses were supplied only in the counties that had ekiro, and were used only by the officials of provincial capitals on their way to their new posts. Following its revival in the ninth century, the character of the tenma system differed from that of the eighth, and it may be regarded as the assistant to the eki system.