Can automated road vehicles harmonize with traffic flow while guaranteeing a safe distance?

Matthias Althoff, Robert Losch

Abstract: A frequently raised argument against safely-driving automated vehicles is that they would not harmonize well with traffic flow-unrealistically large headways would invite other traffic participants to cut in and thus put passengers of following automated vehicles at risk. In order to test this hypothesis, we use real data of thousands of vehicles recorded in the United States as part of the Next Generation Simulation (NGSIM) program. To study the hypothesis, we pretend each human-driven vehicle is automated: These automated vehicles drive exactly as the recorded human drivers, but they have a much smaller reaction time and thus can still drive safely in situations that are unsafe for human drivers. The main result is that in only very few cases an automated vehicle would not drive safely, although more than half of the human drivers do not keep a safe distance according to their capabilities. Thus, there is no increased risk of vehicles cutting in-and if they do, automated vehicles are only at risk in around 10% of all cases compared to around 60% for human drivers.