The Value of Combining Naturalistic Driving Observations with Site-Based Observations: A Pilot Study on the Right-Turn Maneuver

Naturalistic driving studies are increasingly applied in different shapes and sizes. The European project PROLOGUE has investigated the value and feasibility of a large-scale naturalistic driving study in Europe. Within PROLOGUE several pilot studies have been conducted in different countries. The Dutch field trial investigated the value and feasibility of adding site-based observations to in-vehicle observations. In this trial, one intersection was equipped with cameras for site-based observation. Additionally eight cars were equipped with drivers crossing this intersection regularly. On this small scale, combining the two observation methods turned out to be technically feasible. It was possible to match cases from the different observations, and the speed measures from the separate studies appeared to be similar. The value of combining these two observation methods lies in the possibility to enrich the data from one study with complementary data from the other study. From in-vehicle data it is possible to look in detail at the driving behavior of the participants over time and in different situations. The site-based study offers information about the position and speed of other road users surrounding the participant's vehicle, including vulnerable road users such as cyclists and pedestrians. For a future large scale naturalistic driving study two main areas are identified that would benefit from these complementary observations: driving behavior in relation to specific infrastructure and the interaction between drivers and vulnerable road users.