Automated vehicles are gradually entering our roadway system. Before our roads will be solely used by fully automated vehicles, a long transition period is to be expected in which fully automated vehicles, partly automated vehicles and manually-driven vehicles have to share our roads. The current report looked into the position of pedestrians and cyclists in such a future traffic system. The report provides an overview of current knowledge, theoretically and empirically, about the interaction of pedestrians and cyclists with (partly) automated vehicles. Furthermore, it identifies what we need to know in order to ensure that an automated driving system, particularly during the transition period, does not compromise the safety of pedestrians and cyclists.
So far, it can be concluded that automated vehicle technology has mainly focused on the detection and recognition of pedestrians and cyclists by the vehicle and even though good progress has been made, many difficulties are yet to be overcome (e.g., reliable operation in adverse weather conditions). Technology to reliably predict intentions and behaviour of pedestrians and cyclists, so that the automated vehicle can accurately adjust its behaviour is an area that is also crucial for safe interactions between automated vehicles and pedestrians/cyclists. However, this is by no means straightforward because it appears very difficult to predict behavioural intentions of pedestrians and cyclists by current technology. In addition, it cannot be excluded that pedestrians and cyclists will respond differently to (partly) automated vehicles than to manually-driven vehicles.
However, the decision making and behaviour of pedestrians and cyclists in interaction with (partly) automated cars have received very little attention in the research community. Aspects known to determine current interactions, such as formal rules and regulations, informal rules and non-verbal communication, expectations, and behavioural adaptation are likely to play a different role in a system with automated vehicles or in a system with a combination of (partly) automated and manually-driven vehicles. If decisions and behaviour of pedestrians and cyclists towards (partly) automated vehicles are found to be different from their behaviour towards a vehicle driven by a human driver, the software developers cannot base their algorithms on what is known about current interactions and behaviour patterns.
The few studies that did examine the behaviour of pedestrians and cyclists in their interaction with automated vehicles, generally found that they were fairly cautious when interacting with an automated vehicle and not per definition confident of its 'skills'. Furthermore, pedestrians and cyclists were found to appreciate messages and/or signals from the car indicating whether the car has detected them and what it intends to do. However, which exact messages need to be brought about and the method of communicating them are not yet settled and this requires further study.
These and many other questions need to be answered in order to ensure that further developments towards automated driving will not result in a traffic system that is (even) less safe for pedestrians and cyclists than it is presently. Questions, identified in the current report relate, for example, to decision making and behaviour of pedestrians and cyclists when interacting with automated vehicles; the effect of a system with a combination of automated and non-automated vehicles on their behaviour and the options for optimizing the interactions, for example, through training, infrastructure or regulations.
