Characteristics of Speed Dispersion in Urban Expressway
Speed dispersion has tight relation to traffic safety. In this paper, several kinds of indicating parameters (the standard speed deviation, the coefficient of variation, the deviation of V85 and V15, the mean speed deviations, and the difference between adjacent car speeds) are applied to investigate the characteristics of speed dispersion, where V85 and V15 are 85th and 15th percentile speed, respectively. Their relationships are into full investigations and the results show that: there exists a positive relation (linear) between mean speed and the deviation of V85 and V15; while a negative relation (quadratic) between traffic flow and standard speed deviation. The mean speed deviation grows exponentially with mean speed while the absolute speed deviation between adjacent cars grows linearly with the headway. The results provide some basic information for traffic management.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1111975Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 B. S. Kerner, "Three-phase traffic theory and highway capacity," J. Physical A. vol.333, pp.379-440, 2004.
 D. Solomon, Accidents on main rural highways related to speed, drivers, and vehicle, CA: Washington Bureau of Public Roads, 1964.
 G.Z. Cheng and Y.L. Pei, "Research on the relationship between discrete character of speed and traffic accident and speed management of freeway." J. China Journal of Highway & Transport., vol.17, pp.74-78, 2004.
 F.Q. Lu and X. Chen, "Analyzing the Speed Dispersion Influence on Traffic Safety," in 2009 International Conference on Measuring Technology and Mechatronics Automation (ICMTMA 2009), pp.482-485, 2009.
 A. Baruya, "Speed accident relationships on different kinds of European roads," Transportation Research Laboratory, London, Tech. Rep., 1998.
 G. Peng, H. He, W.Z. Lu, et al., "A new car-following model with the consideration of incorporating timid and aggressive driving behaviors," J. Physica A: Statistical Mechanics & Its Applications, vol. 442, 2015.
 B. Ponnu, B. Coifman, F. Mannering, "peed-spacing dependency on relative speed from the adjacent lane: New insights for car following models," J. Transportation Research Part B: Methodological, vol.82, pp. 74-90, 2015.
 L. Liu, L. Zhu, and D. Yang," Modeling and simulation of the car-truck heterogeneous traffic flow based on a nonlinear car-following model," J. Applied Mathematics & Computation, vol. 273, pp.706-717, 2016.
 W.J. Pienaar, US Highway Capacity Manual, CA: Civil Engineering, 1986.