Theoretical conditions for restricting secondary jams in jam-absorption driving scenarios

Abstract

There has been considerable interest in the active maneuvers made by a small number of vehicles to improve macroscopic traffic flows. Jam-absorption driving (JAD) is a single vehicle's maneuvers to remove a wide moving jam and consists of two actions. First, a vehicle upstream of the jam slows down and maintains a low velocity. Because it cuts off the supply of vehicles to the jam, the jam shrinks and finally disappears. Second, it returns to following the vehicle ahead of it. One of the critical problems of JAD is the occurrence of secondary jams. The perturbations caused by JAD actions may grow into secondary jams due to the instability of traffic flows. The occurrence of secondary jams was investigated by numerical simulations in non-periodic systems where only human-driven vehicles are placed upstream of the vehicle performing JAD. However, no theoretical condition has been proposed to restrict secondary jams in these systems. This paper presents a theoretical condition restricting secondary jams in a semi-infinite system composed of a vehicle performing JAD and the other human-driven vehicles obeying a car-following model on a non-periodic and single-lane road. In constructing this condition, we apply the linear string stability to a macroscopic spatiotemporal structure of JAD. Numerical simulations show that a finite version of this condition restricts secondary jams. Moreover, under this condition, we demonstrate that it is possible to restrict secondary jams in the semi-infinite system under wide ranges of the parameters of the system. Furthermore, we construct the conditions suppressing secondary jams in other semi-infinite systems with inflows from other lanes or a bottleneck, and demonstrate that JAD can restrict secondary jams in these systems. Thus, our method theoretically guarantees that a single vehicle can improve macroscopic traffic flows.

Assessing the Impact of CAV Driving Strategies on Mixed Traffic on the Ring Road and Freeway

“…And some researchers also use the IDM model and the Newell model [24] for modeling [25]. At the same time, the theoretical conditions for restricting secondary jams in jam-absorption driving scenarios were derived [26].…”

System-size dependence of a jam-absorption driving strategy to remove traffic jam caused by a sag under the presence of traffic instability

“…Subsequently, the absorbing vehicle promptly returns to following the preceding vehicle as the fast-out phase. The performance of JAD has been investigated numerically and/or theoretically using kinematic [23] and car-following [24][25][26][27][28] models, and experimentally using real vehicles on a circuit [29]. Strategies in this direction has been studied diligently [30][31][32][33][34][35][36][37], and has been also developed as the Lagrangian control of moving bottlenecks [38][39][40][41], and the speed harmonization [42][43][44][45].…”

“…In this study, we focus on the second type as the target traffic jam, and consider a bottleneck on a highway road. Researchers have treated various bottleneck types or effects: fixed bottleneck (such as traffic accidents, work zones, and obstacles) [38,39,[51][52][53], lane reduction [49,54,55], on-ramp [45][46][47]53], rubbernecking in a specific region [25], imposition of capacity drop [27,56,57], and sag [58][59][60][61]. Among various bottlenecks on highways, this study focuses on sag.…”

“…Various strategies manipulate special vehicles to improve highway traffic at bottlenecks. Examples of them include trajectory planning [49], changing the settings of adaptive cruise control according to the traffic situation [46], running slowly upstream of traffic jam [38,39,47,53,58,59,61], maneuvers combining deceleration and acceleration [60], maneuvers produced by reinforcement learning [54,55], reinforcement learning of merge control and speed harmonization [52], combination of cooperative adaptive cruise control platooning, cooperative merge, and speed harmonization [45], and the maneuvers aiming to remove the traffic jam such as Pacer Cars [22], speed harminization [57], dynamic VSL with CVs [56], and JAD [25,27]. Among these strategies, this study focuses on JAD.…”

“…When an absorbing vehicle performs JAD to clear a traffic jam, its actions cause perturbations to the upstream traffic flow. Such a perturbation may grow into new traffic jam (also known as the secondary traffic jam) [24][25][26][27]37]. The secondary traffic jam has been also reported and investigated in the SPECIALIST and related strategies [10,[62][63][64].…”