It has only been forty years or so since road development and improvement in Japan hit its stride. However, the construction of new roads has failed to keep up with the increase in automobile traffic and, as a result, congestion occurs in many locations. In order to alleviate this problem, the 11th Five-Year Plan calls for expenditure totalling 76 trillion Yen and stresses quantitative expansion. Revision of the Road Structure Act is currently underway, uniting the power of Japanese road organisations with the objective of improving the road quality before the 21st century. One of the major tasks of this revision is the method of deciding on the number of lanes for the integration of highway capacity and amount of traffic. This paper discusses the concept of highway capacity in Japan and comments on its future. (A)
Abstract