Impacts of Cooperative Adaptive Cruise Control on Freeway Traffic Flow

Abstract

This study used microscopic simulation to estimate the effect on highway capacity of varying market penetrations of vehicles with adaptive cruise control (ACC) and cooperative adaptive cruise control (CACC). Because the simulation used the distribution of time gap settings that drivers from the general public used in a real field experiment, this study was the first on the effects of ACC and CACC on traffic to be based on real data on driver usage of these types of controls. The results showed that the use of ACC was unlikely to change lane capacity significantly. However, CACC was able to increase capacity greatly after its market penetration reached moderate to high percentages. The capacity increase could be accelerated by equipping non-ACC vehicles with vehicle awareness devices so that they could serve as the lead vehicles for CACC vehicles.

Modeling and simulations on automated vehicles to alleviate traffic congestion

“…The simulation of each traffic flow is composed of several iterations. In the process of horizontal lane changing, the human driven vehicles perform the basic NaSch model, automated vehicles perform the following improved model [13]:…”

Multi-Resolution Modeling of Managed Lanes with Consideration of Autonomous/Connected Vehicles

“…As stated earlier, the lane capacity as a function of the proportions of ACC/ CACC vehicles was estimated by Shladover et al (2012), using microscopic sim0ulation to estimate the effect of different market penetrations of ACC and CACC on freeway capacity. The distribution of time gap settings that drivers used in a real field test was used in the simulation.…”

“…The distribution of time gap settings that drivers used in a real field test was used in the simulation. In the study conducted by Shladover et al (2012), it was necessary to develop and validate several mathematical models such as car-following logic for each operational mode, merging of vehicles entering from an on-ramp, and free driving of a vehicle in uncongested condition.…”

“…Shladover et al (2012) applied microscopic simulation modeling to estimate the effect of different market penetrations of ACC and CACC on highway capacity. They used AIMSUN, which is a microscopic simulation tool because it was the only simulation tool, in which the NGSIM model of oversaturated freeway flow could be implemented to provide the most realistic representation of manually drivers' car-following behavior in congested conditions.…”

“….47 Table 3-3 Simulation Results for Different Percentage of CACC (Shladover et al, 2012 Modeling of transportation systems is an essential component of transportation system planning and engineering. Transportation modeling tools are generally categorized as sketch planning, macroscopic, mesoscopic, or microscopic based on the resolution in which traffic flows are simulated.…”