Study of congestion phenomena at tunnels and sags on motorways

Masaki Koshi, Masao Kuwahara, Hirokazu Akahane

Research output: Contribution to journalArticle

2 Citations (Scopus)


It has been recognized since early 1980's that some of tunnels as well as vertical alignment sags in Japanese motorways tend to be capacity bottlenecks. This paper reports several facts observed at these bottlenecks and presents our hypothesis on the reason and the mechanism of the low capacities. Capacity values which are considerably lower than the usual capacity values of normal sections at the start of congestion, become even lower once the queue forms and further lower as the queue grows longer. This paper suggests that the driver's car following behavior which determines the capacity seems to relate to the time duration that the drivers have spent in the queue as well as to the light conditions.

Original languageEnglish
Pages (from-to)65-71
Number of pages7
JournalDoboku Gakkai Rombun-Hokokushu/Proceedings of the Japan Society of Civil Engineers
Issue number458 pt 4-18
Publication statusPublished - 1993 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Engineering(all)

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