The study on the effect of lane change maneuvers on a simplified car-following theory

A recent paper by Newell proposed a simplified car-following theory based on a novel logic. The basic assumption for this theory is that spacing and vehicle velocity are linearly related. Several other researchers studying wave speeds through the traffic stream have since found empirical evidence supporting Newell's simplified car-following theory. However, these earlier efforts have not explicitly verified the aforementioned basic assumption and in fact they have found that Newell's theory fails in the presence of frequent lane change maneuvers without providing detailed analyses. Taking a different approach, our paper studies the spacing velocity relationship using vehicle trajectory data collected during congestion, upstream of an on-ramp, where lane changing is infrequent. The empirical results show that a lane change maneuver perturbs the linear spacing velocity relationship. However, despite the disturbances from lane change maneuvers, the assumption of the linear relationship between spacing and velocity is reasonable most of the time for the vehicles on the study segment.