Abstract
Freeway capacity decreases at sags due to local changes in car-following behavior. Consequently, sags are often bottlenecks in freeway networks. This article presents a microscopic traffic model that reproduces traffic flow dynamics at sags. The traffic model includes a new car-following model that takes into account the influence of freeway gradient on vehicle acceleration. The face-validity of the traffic model is tested by means of a simulation study. The study site is a sag of a Japanese freeway. The simulation results are compared to empirical traffic data presented in previous studies. We show that the model is capable of reproducing the key traffic phenomena that cause the formation of congestion at sags, including the lower capacity compared to normal sections, the location of the bottleneck around the end of the vertical curve, and the capacity drop induced by congestion. Furthermore, a sensitivity analysis indicates that the traffic model is robust enough to reproduce those phenomena even if some inputs are modified to some extent. The sensitivity analysis also shows what parameters need to be calibrated more accurately for real world applications of the model.
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.References
Koshi, M., Kuwahara, M., Akahane, H.: Capacity of sags and tunnels on Japanese motorways. Inst. Transp. Eng. J. 62(5), 17–22 (1992)
Okamura, H., Watanabe, S., Watanabe, T.: An empirical study on the capacity of bottlenecks on the basic suburban expressway sections in Japan. Proceedings of the 4th International Symposium on Highway Capacity, Maui, Hawaii (2000)
Brilon, W., Bressler, A.: Traffic flow on freeway upgrades. Transp. Res. Rec. 1883, 112–121 (2004)
Furuichi, T., Yamamoto, S., Kotani, M., Iwasaki, M.: Characteristics of spatial speed change at motorway sag sections and capacity bottlenecks. Proceedings of the 82nd Annual Meeting of the Transportation Research Board, Washington, D.C. (2003)
Koshi, M.: An interpretation of a traffic engineer on vehicular traffic flow. In: Fukui, M., Sugiyama, Y., Schreckenberg, M., Wolf, D.E. (eds.) Traffic and Granular Flow 01, pp. 199–210. Springer, Berlin (2003)
Yoshizawa, R., Shiomi, Y., Uno, N., Iida, K., Yamaguchi, M.: Analysis of car-following behavior on sag and curve sections at intercity expressways with driving simulator. Int. J. Intell. Transp. Syst. Res. 10(2), 56–65 (2012)
Goñi Ros, B., Knoop, V.L., van Arem, B., Hoogendoorn, S.P.: Empirical analysis of the causes of stop-and-go waves at sags. IET Intell. Transp. Syst. 8(5), 499–506 (2014)
Hatakenaka, H., Hirasawa, T., Yamada, K., Yamada, H., Katayama, Y., Maeda, M.: Development of AHS for traffic congestion in sag sections. Proceedings of the 13th ITS World Congress, London, U.K. (2006)
Patire, A.D., Cassidy, M.J.: Lane changing patterns of bane and benefit: observations of an uphill expressway. Transp. Res. B 45(4), 656–666 (2011)
Xing, J., Sagae, K., Muramatsu, E.: Balance lane use of traffic to mitigate motorway traffic congestion with roadside variable message signs. Proceedings of 17th ITS World Congress, Busan, South Korea (2010)
Hall, F.L., Agyemang-Duah, K.: Freeway capacity drop and the definition of capacity. Transp. Res. Rec. 1320, 91–98 (1991)
Komada, K., Masukura, S., Nagatani, T.: Effect of gravitational force upon traffic flow with gradients. Phys. A 388, 2880–2894 (2009)
Yokota, T., Kuwahara, M., Ozaki, H.: A study of AHS effects on traffic flow at bottlenecks. Proceedings of the 5th ITS World Congress, Seoul, South Korea (1998)
Oguchi, T., Konuma, R.: Comparative study of car-following models for describing breakdown phenomena at sags. Proceedings of the 19th ITS World Congress, Stockholm, Sweden (2009)
Treiber, M., Hennecke, A., Helbing, D.: Congested traffic states in empirical observations and microscopic simulations. Phys. Rev. E. 62(2), 1805–1824 (2000)
Schakel, W., Knoop, V.L., van Arem, B.: Integrated lane change model with relaxation and synchronization. Transp. Res. Rec. 2316, 47–57 (2012)
Wu, N.: Equilibrium of lane flow distribution on motorways. Transp. Res. Rec. 1965, 48–59 (2006)
Papageorgiou, M., Diakaki, C., Dinopoulou, V., Kotsialos, A., Wang, Y.: Review of road traffic control strategies. Proc. IEEE 91, 2043–2067 (2003)
Acknowledgments
This research was sponsored by Toyota Motor Europe. The authors would like to thank the anonymous reviewers for their valuable comments and suggestions to improve the quality of the paper.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Goñi Ros, B., Knoop, V.L., Shiomi, Y. et al. Modeling Traffic at Sags. Int. J. ITS Res. 14, 64–74 (2016). https://doi.org/10.1007/s13177-014-0102-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13177-014-0102-3