Development of a Connected Vehicle Dynamic Freeway Variable Speed Controller

Abstract

Traffic congestion is a major challenge in urban areas, and is associated with longer travel times, increased vehicle emissions, and numerous vehicle crashes. Creating an efficient mobility system is difficult, given that each driver is usually trying to optimize their individual trip within the network without accounting for other road users. However, new technologies in modern vehicles, especially connected vehicle technologies, make it increasingly possible to find solutions to network efficiency problems. Connected technologies allow data sharing between vehicles, allowing for greater system optimization. This work takes advantage of connectivity to develop a global framework to increase transportation network efficiency and address the aforementioned challenges. To enhance mobility, this paper presents a dynamic freeway speed controller based on the sliding mode theory, which uses the fundamental equations governing traffic dynamics in combination with variable speed limit control in order to provide advisory speeds for connected vehicles. Simulation results on a downtown Los Angeles network show significant reductions in trip times and delays both on freeways (where the control was activated) and network-wide (i.e., freeways and other roadways). Specifically, the results for the entire network showed a 12.17% reduction in travel time and a 20.67% reduction in total delay. These results had the secondary effect of reducing fuel consumption and therefore CO 2 emissions by 2.6% and 3.3%, respectively. The results for the freeway network alone showed a 20.48% reduction in travel time and a 21.63% reduction in queued vehicles. These results reveal the significant potential benefits of using the proposed speed harmonization controller on real large-scale networks. INDEX TERMS Connected vehicles, large scale network, sliding control, speed harmonization, variable speed control.

Environmental and Safety Impacts of Vehicle-to-Everything Enabled Applications: A Review of State-of-the-Art Studies

“…The results showed that average travel time was reduced by 12%, total delay was reduced by 21%, and CO2 emissions were reduced by 3.3%. In addition, the authors' results showed that freeways benefit from the controller more than arterials [10].…”

Evaluating an Eco-Cooperative Automated Control System

“…This SPD-HARM controller, based on a sliding mode controller, was applied only to freeway sections. Abdelghaffar et al designed an SPD-HARM controller that regulates vehicle speeds in a speed harmonization zone to maintain downstream link vehicle speeds at the speed of capacity ( 4 , 54 ). The SPD-HARM controller is dynamic, does not require prior knowledge of bottleneck locations, and delivers recommended speeds to the vehicles on the network.…”

“…The objective is to keep the speed of link l , which is congested or about to be congested, v l , close to its speed at capacity v l true¯ . A detailed description of the SPD-HARM appears in Abdelghaffar et al ( 4 , 54 ).…”

A systematic literature review of vehicle speed assistance in intelligent transportation system

“…In a more recent study, Abdelghaffar et al. have proposed a dynamic freeway speed controller to overcome vehicle emissions and crashes by decreasing the number of stops caused by traffic congestion [57]. They have presented the method based on sliding theory and CV environment.…”