In car-following procedure, some distances are reserved between the vehicles, through which drivers can avoid collisions with vehicles before and after them in the same lane and keep a reasonable clearance with lateral vehicles. This paper investigates characters of vehicle operating safety in car following state based on required safe distance. To tackle this problem, we probe into required safe distance and car-following model using molecular dynamics, covering longitudinal and lateral safe distance. The model was developed and implemented to describe the relationship between longitudinal safe distance and lateral safe distance under the condition where the leader keeps uniform deceleration. The results obtained herein are deemed valuable for car-following theory and microscopic traffic simulation. 1. Introduction Car-following models elaborate the situation that vehicles follow one another in the same lane and capture drivers’ maneuvering decisions under different conditions. The models are the most fundamental part of microscopic traffic simulation [1]. From the research of Reuschel and Pipes using the operational research theory method on car-following, the models can be classified as stimulus-response models (Gazis et al., 1961; Newell, 1961), safe distance models (Gipps, 1981), psychophysical models (Wiedemann, 1974), and artificial intelligence models (Kikuchi and Chakroborty, 1992; Wu et al., 2000) [2–6]. Among them, the car-following model based on the safe distance has broadly been used in practice [7]. Parker put forward an expectation distance model for the first time through the research on car-following behavior on the fast road sections [8]. Peter Hides carried out further research on microscopic behavior of urban traffic flow and preliminarily established car-following models for urban traffic flow based on expectation distance [9]. Zhang et al. gave deep research on psychological and physical reaction mechanism of the driver and presented multiregime model based on the driver's psychological reaction [10]. At present, the car-following model based on safe distance has been widely applied to microscopic simulation of road traffic, which is one of the hot research topics in the field of traffic engineering [11, 12]. Reaction time for a car-following maneuver responding to an unexpected hazard in the roadway has been conducted in several studies [13–18]. From their results, the mean reaction times identified are rarely greater than 1.50 seconds. The safe distances in the articles above all gave the longitudinal clearance from a preceding
References
[1]
T. Toledo, “Driving behaviour: models and challenges,” Transport Reviews, vol. 27, no. 1, pp. 65–84, 2007.
[2]
D. C. Gazis, R. Herman, and R. W. Rothery, “Nonlinear follow-the-leader models of traffic flow,” Operation Research, vol. 9, no. 4, pp. 545–567, 1961.
[3]
G. F. Newell, “Nonlinear effects in the dynamics of car following,” Operation Research, vol. 9, no. 2, pp. 209–229, 1961.
[4]
P. G. Gipps, “Behavioral car-following model for computer simulation,” Transportation Research B, vol. 15, no. 2, pp. 105–111, 1981.
[5]
R. Wiedemann, Simulation of Road Traffic in Traffic Flow, University of Karlsruhe, Karlsruhe, Germany, 1974.
[6]
C. Kikuchi and P. Chakroborty, “Car following model based on a fuzzy inference system,” Transportation Research Record, vol. 1194, pp. 82–91, 1992.
[7]
M. F. Aycin and R. F. Benekoha, “Comparison of car-following models for simulation,” in Proceedings of the 78th Annual Meeting of Transportation Research Board (TRB '99), 1999.
[8]
M. T. Parker, “The effect of heavy goods vehicles and following behaviour on capacity at motorway roadwork sites,” Traffic Engineering & Control, vol. 37, no. 9, pp. 524–531, 1996.
[9]
H. Peter, “A car-following model for urban traffic simulation,” Traffic Engineering & Control, vol. 39, no. 5, pp. 300–302, 1998.
[10]
Y. L. Zhang, J. E. Clark, and E. C. James, “A multivegime approach for microscopic traffic simulation,” in Proceedings of the 77th Annual Meeting of Transportation Research Board (TRB '98), Washington, DC, USA, 1998.
[11]
S. Druitt, “An introduction to microsimulation,” Traffic Engineering & Control, vol. 39, no. 9, pp. 480–483, 1998.
[12]
E. R. Boer, “Car following from the driver's perspective,” Transportation Research F, vol. 2, no. 4, pp. 201–206, 1999.
[13]
D. B. Fambro, R. J. Koppa, D. L. Picha, and K. Fitzpatrick, “Driver perception-brake response in stopping sight distance situations,” Journal of the Transportation Research Board, vol. 1628, pp. 1–7, 1998.
[14]
K. I. Ahmed, Modeling driver's acceleration and lane changing behaviors [Ph.D. thesis], Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 1999.
[15]
G. S. Gurusinghe, T. Nakatsuji, Y. Tanaboriboon, K. Takahashi, and J. Suzuki, “A car-following model incorporating excess critical speed concept,” Journal of Eastern Asia Society for Transportation Studies, vol. 4, no. 2, pp. 171–183, 2001.
[16]
P. Ranjitkar, T. Nakatsuji, G. Gurusinghe, and Y. Azuta, “Car-following experiments using RTK GPS and stability characteristics of followers in platoon,” in Proceedings of the 7th International Conference on Applications of Advanced Technology in Transportation, pp. 608–615, Boston, Mass, USA, 2002.
[17]
Y. Uchiyama, K. Ebe, A. Kozato, T. Okada, and N. Sadato, “The neural substrates of driving at a safe distance: a functional MRI study,” Neuroscience Letters, vol. 352, no. 3, pp. 199–202, 2003.
[18]
J. S. Kong, F. Guo, and X. P. Wang, “A vehicle rear-end anti-collision method base on safety distance model,” Automotive Electronics, vol. 24, no. 11, pp. 251–253, 2008.
[19]
B. Gunay, “Car following theory with lateral discomfort,” Transportation Research B, vol. 41, no. 7, pp. 722–735, 2007.
