Tsinghua Science and Technology


Eco-Approach and Departure (EAD), Surrogate Safety Assessment Model (SSAM), safety analysis, conflict type, Time-To-Collision (TTC)


Various intelligent transportation systems and strategies for reducing vehicle fuel consumption andemissions have been developed. Energy and emissions could be reduced with the compromise of travel time in some environment-focused Connected Vehicle (CV) applications, which highlighted performance measures in terms of mobility and sustainability. Nevertheless, few studies have focused on safety assessment of such CV applications. In this study, a CV-based eco-driving application, namely, Eco-Approach and Departure (EAD), is selected as an example. A microscopic safety analysis tool, Surrogate Safety Assessment Model (SSAM), is utilized to assess the safety influence of EAD application in multiple scenarios. Further analysis is performed from two perspectives: (1) application users, i.e., EAD-equipped vehicles versus unequipped vehicles; and (2) traffic operators, i.e., overall traffic performance with and without the introduction of EAD. For each perspective, conflict statistics (e.g., frequency, time-to-collision distribution), overall and by type, are analyzed. Results indicate EAD is beneficial in improving the safety performance of equipped vehicles. The influence of EAD on overall traffic is scenario dependent, and a high penetration rate shows positive effects on network-wide safety benefits for most scenarios.


Tsinghua University Press