  Lane changes are complex driving behaviors and frequently involve
safety-critical situations. This study aims to develop a lane-change-related
evasive behavior model, which can facilitate the development of safety-aware
traffic simulations and predictive collision avoidance systems. Large-scale
connected vehicle data from the Safety Pilot Model Deployment (SPMD) program
were used for this study. A new surrogate safety measure, two-dimensional
time-to-collision (2D-TTC), was proposed to identify the safety-critical
situations during lane changes. The validity of 2D-TTC was confirmed by showing
a high correlation between the detected conflict risks and the archived
crashes. A deep deterministic policy gradient (DDPG) algorithm, which could
learn the sequential decision-making process over continuous action spaces, was
used to model the evasive behaviors in the identified safety-critical
situations. The results showed the superiority of the proposed model in
replicating both the longitudinal and lateral evasive behaviors.
