Heterogeneous platoon flow dispersion model based on truncated mixed simplified phase‐type distribution of travel speed

Abstract

Existing research on platoon dispersion models either describe homogeneous traffic flow feature, or are in lack of analytical solutions. By analyzing the field data, the truncated mixed simplified phase-type distribution is proved to be capable of capturing the characteristics of heterogeneous traffic flow with an excellent fitting result. In light of this, we derive a generic heterogeneous platoon dispersion model with truncated mixed simplified phase-type of speed in the forms of integrable functions. Numerical case studies are conducted to compare the performance of the proposed model and the conventional models (i.e., the Robertson model and truncated mixed Gaussian model). The results show that the proposed model not only better captures the platoon dispersion laws of heterogeneous traffic flow, but also presents higher computational efficiency, which provides practical implications on traffic signal control.Although the PH distribution can approximate any non-negative random variables infinitely in theory (e.g., the distribution of travel speed and travel time), it contains as many as m 2 + m parameters 2162 JIANG Y. ET AL.

Real-Time Prediction of Lane-Based Queue Lengths for Signalized Intersections

“…Because the tail of the geometric distribution is longer than the corresponding normal distribution, Robertson's model can better predict the platoon dispersion for any given mean travel time [41]. In addition, because of the low computational requirements of Robertson's model, it is easy to apply this model both to the signal optimization of large road networks [37,[42][43][44] and to the development of other traffic theories [31,[45][46][47][48][49].…”

An Arterial Green-Wave Synchronous Coordination Model for Bus and Non-bus Lanes Based on Platoon Dispersion Theory

“…Therefore, accurately describing the time-space dispersion characteristics of platoons based on the traffic flow data of vehicles upstream of intersections is key to the effective coordination of traffic. Two models are commonly used to describe platoon dispersion, including Robertson's model [15,16] and Pacey's model [17][18][19][20][21][22][23]. Robertson's model can be applied to roads with frequent intersections, while Pacey's model can be applied to roads with sparse intersections [17].…”

“…These two models vary slightly in accuracy and efficiency [18,19]. The theory of platoon dispersion can be used to describe the time-space dispersive characteristics of buses and private vehicles while considering the green-wave coordination control objectives of both bus and non-bus lanes [20][21][22][23]. Therefore, the coupling relationships among the traffic flows between two adjacent intersections on two-lane roadways and signal timing can be determined using the platoon dispersion characteristics of private and non-private vehicles.…”

Dynamic platoon dispersion model based on real‐time link travel time

“…Previous studies of platoon dispersion model mainly focus on two aspects: (i) new methods to calibrate Robertson's platoon dispersion model under different traffic condition [5][6][7][8][9][10] and (ii) new heterogeneous platoon dispersion models based on the mixed probability distribution [11][12][13][14]. However, all these studies [5][6][7][8][9][10][11][12][13][14] were based on historical data, which cannot effectively capture the dynamic characteristics of traffic flow. In urban roads, the real-time traffic flow changes due to complex conditions, such as weather, accident, time, work zone, and so on [15][16][17].…”