Teddy bears and driving automation: an on-road paradigm to evaluate situational awareness

March 2021

This paper discusses the lessons learned from the development of a novel paradigm in an on-road observation study that explored human factors issues when using Level 2 driving automation. There is the risk that drivers may become disengaged from the driving task when using these partially automated systems, but current production Level 2 systems vary between manufacturers in terms of their functional performance and driver management strategies. On-road methodologies are needed to objectively evaluate the degree of disengagement drivers may experience when behind the wheel of these types of vehicles. This paper presents a proof of concept of an experiment that involved an approximately 1-hour drive along a predetermined route in a 2019 Mercedes-Benz C300 equipped with a Level 2 system. The paradigm was designed to assess drivers’ inattentional blindness to three driving-related surprise events, thereby providing a measure of situational awareness. Using GPS data from the participant’s vehicle and another study vehicle, the other vehicle overtook the participant at three predetermined locations. The "surprise" nature of each event was an oversized pink teddy bear wearing a high-visibility jacket that was mounted to the back of the other study vehicle. Situational awareness was evaluated in a post-drive survey in which participants had to recall the bear and how many times they had seen it on the road. The aim of this paper is to help inform future research using on-road driving methods, particularly as they relate to the use of Level 2 driving automation, by using insights gained from this study’s experimental procedure, vehicle equipment, and data collection protocols.