Platoons of connected vehicles can double throughput in urban roads

Abstract

Intersections are the bottlenecks of the urban road system because an intersection's capacity is only a fraction of the maximum flows that the roads connecting to the intersection can carry. This capacity can be increased if vehicles cross the intersections in platoons rather than one by one as they do today. Platoon formation is enabled by connected vehicle technology. This paper assesses the potential mobility benefits of platooning. It argues that saturation flow rates, and hence intersection capacity, can be doubled or tripled by platooning. The argument is supported by the analysis of three queuing models and by the simulation of a road network with 16 intersections and 73 links. The queuing analysis and the simulations reveal that a signalized network with fixed time control will support an increase in demand by a factor of (say) two or three if all saturation flows are increased by the same factor, with no change in the control. Furthermore, despite the increased demand vehicles will experience the same delay and travel time. The same scaling improvement is achieved when the fixed time control is replaced by the max pressure adaptive control. Part of the capacity increase can alternatively be used to reduce queue lengths and the associated queuing delay by decreasing the cycle time. Impediments to the control of connected vehicles to achieve platooning at intersections appear to be small.

Effect of adaptive and cooperative adaptive cruise control on throughput of signalized arterials

“…As a result ordinary as well as (C)ACC vehicles benefit from lower average travel times with a lower standard deviation. The results of this paper together with those in [5] indicate that (C)ACC can greatly improve urban road mobility at little or no additional infrastructure cost.…”

“…In the experiment with the red light downstream we study the impact of this braking effect on the throughput of the first intersection. (This is the second limitation noted in [5]. )…”

“…So increasing the latter capacity by platooning will do nothing to increase the capacity of the road network. This observation is at the core of the remarkable study [5] to increase the throughput or saturation flow rate of an intersection by having cars cross the intersection in a platoon of ACC or CACC vehicles. The study concludes: if the saturation flow rates at all intersections in an urban network is increased by a factor Γ, "the network can support an increase in demand by the same factor Γ, with no increase in queuing delay or travel time, and using the same signal control.…”

Securing Connected & Autonomous Vehicles: Challenges Posed by Adversarial Machine Learning and the Way Forward

“…The key purpose of initiating and investigating such projects is to reduce energy consumption and personnel costs by automated operation of following vehicles. Furthermore, it has been suggested in the literature that throughput on urban roads can be doubled using vehicle platooning [28].…”

Planning of truck platoons: A literature review and directions for future research

“…Furthermore, platooning can enhance traffic safety by providing significantly lower reaction times and less room for human error within the platoon, which can reduce the number of rear-end collisions. Also, trucks in a platoon take up less 20 road space than when driving separately, which reduces traffic congestion Van Arem et al, 2006) and therefore, increases traffic throughput (Lioris et al, 2017).…”