Reducing Side-sweep Accidents with Vehicle-to-Vehicle Communications

This dissertation present contributions to the understanding of the causes of a side-sweep accidents on multi-lane highways using computer simulation. Side-sweep accidents are one of the major causes of loss of life and property damage on highways. This type of accident is caused by a driver initiating a lane change while another vehicle is blocking the road in the target lane. Our objective in the research described in this dissertation was to understand and simulate the different factors which affect the likelihood of side sweep accidents. For instance, we know that blind spots, parts of the road that are not visible to the driver directly or through the rear-view mirrors are often a contributing factor. Similarly, the frequency with which a driver checks his rear-view mirrors before initiating the lane change affects the likelihood of the accident. We can also have an intuition that side-sweep accidents are more likely if there is a significant difference in the vehicle velocities between the current and the target lanes. There are also factors that can reduce the likelihood of the accident: for instance, the signaling of the lane change by the driver can alert the nearby vehicles about the lane change, and they can change their behaviors to give way to the lane changing vehicle. The emerging technology of vehicle-to-vehicle communication offers promising new avenues to avoid such collisions by making vehicles communicate the lane change intent and their positions, such that automatic action can be taken to avoid the accident. While we can have an intuition about whether some factors increase or reduce accident rate, these factors interact with each other in complex ways. The research described in this dissertation developed a highway driving simulator specialized for the accurate simulation of the various factors which contribute to the act of lane change in highway driving. We are modeling the traffic as seen from the lane changing vehicle, including the density, distribution and relative velocity of the vehicles on the target lane. We are also modeling the geometry of the vehicle, including size, windows, mirrors, and blind spots. Moving to the human factors of the simulation, we are modeling the behavior of the driver with regards to the times of checking the mirrors, signalling and making the lane change decision. Finally, we are also modeling communication, both using the traditional way using the turn signals, as well as through means of automated vehicle to vehicle communication. The detailed modeling of these factors allowed us to perform extensive simulation studies that allow us to study the impact of various factors on the probability of side-sweep accidents. We validated the simulation models by comparing the results with the real-world observations of the National Highway Traffic Safety Administration. One of the benefits of our model is that it allows the modeling of the impact of vehicle to vehicle communication, a technology currently in prototype stage, that cannot be studied in extensive real world scenarios