CLR Analytics


Evaluating System Impacts of Automated Vehicles: A Multiple-Resolution Modeling Approach

The rapid development of automated vehicles has attracted a lot of attentions from the public in recent years. Current studies on automated vehicles mainly focus on microscopic simulations with simple network topologies and driver behaviors, and few has considered to incorporate automated vehicles into macroscopic travel demand models for the analysis in a regional network.

In this project, we propose an Automated Vehicle System Impacts Evaluation Module, AVSIEM, for both transportation and traffic operation analysis using a two-step multi-resolution modeling approach. The approach involves the use of microsimulation to quantify the capacity improvement through a capacity adjustment factor (CAF), which is then applied in the macroscopic travel demand model to evaluate AVs’ impacts on regional networks. To implement the approach, an integrated car-following and car-control model was developed to model the mixed traffic flow with human driving vehicles and AVs. The car-following model parameters of the integrated model were calibrated using vehicle trajectory data from the NGSIM datasets.

AV Evaluation

The proposed approach was successfully demonstrated for its effectiveness. The completed tasks include:

  1. A comprehensive review of existing car-following models and regional transportation models;
  2. Development of an integrated car-following model for both human drivers and automated vehicles;
  3. Implementation of the integrated car-following model as a plugin in microsimulation;
  4. Calibration of the integrated car-following using vehicle trajectory data from the real-world;
  5. Prototype roadway networks to evaluate the single-lane link performance with the application of automated vehicles for different road geometries and signal control settings;
  6. Development of the CAF to address the impacts of automated vehicles using microsimulation; and
  7. Commercialization analysis to show potential applications of AVSIEM.

The commercial analysis shows that the products and services from the study can address urgent market needs from federal and state government agencies as well as the private sectors. The following products can be further developed:

  1. microscopic traffic simulation plugins to model AVs;
  2. travel demand modeling plugin to evaluate the impacts of AVs; 
  3. customizable CAF lookup table to work with local travel demand models; and
  4. a traffic simulation based automated and connected vehicle evaluation platform. 

Sponsor: USDOT/RITA/Volpe Center
Project Time Period: September 2015 – Mar 2016 (Phase I)