Understanding and Predicting Overtaking and Fold-Down Lane-Changing Maneuvers on European Highways Using Naturalistic Road User Data*

Understanding and predicting lane-changing in-tents on highways is fundamental for multi-lane cruise control systems and automated driving. Many studies have been carried out using the NGSIM data-set of trajectories on US highways with symmetric lane-changing behaviors. In this contribution, we present a statistical analysis of discretionary lane-changing maneuvers on German two-lane highways imposing overtaking to the left only (highD project). We aim to separately identify the underlying mechanisms that motivate drivers to overtake and to fold-down. The analysis is done using principal component analysis and logistic regressions based on speed-difference and distance variables with the four surrounding vehicles. The results show that two different mechanisms operate in case of overtaking and fold-down. Overtaking can be explained monotonically with only three variables: the distance and speed difference with the predecessor and the speed difference with the following vehicle on the adjacent lane. Fold-down is a more complex process involving more variables and relationships. The predictions based on the logistic regression are accurate for lane-keeping but limited for lane-changing maneuver, especially for fold-down. The limitations are due to non-linear behaviors of the fold-down maneuver for which the logistic regression is insensitive.