I. Introduction
Merging into a high-speed traffic flow, such as traffic on expressways, is one of the most demanding driving tasks for drivers [1], [2], because merging requires multiple tasks, e.g., cognition, decision-making, and driving operations [3], [4]. These parallel tasks can be achieved by drivers with some level of driving experience and skill. For example, Mitchell et al. concluded that elderly drivers often merge at the end of an acceleration lane [5]. Reducing difficulties in either cognition, decision-making, or driving operations can decrease overlapping tasks and realize safe and low-loading merge.