Strategies and spacing requirements for lane changing and mergingin automated highway systems

摘要

In automated highway systems (AHS) vehicles are expected tonoperate using their own sensing and control systems by interacting withnother vehicles and the infrastructure in a way that guarantees safety,nstability, and high capacity. We examine various alternative scenarianfor merging and lane changing and we present an algorithm forncalculating the minimum safety spacing for lane changing (MSSLC); thatnis, we calculate the intervehicle spacing that the vehicles shouldnmaintain during a merging or lane changing maneuver so that in the casenwhere one of the vehicles executes an emergency braking manuever, thenrest of the vehicles have enough time and space to stop without anyncollision taking place. The calculation of the MSSLCs for merging ornlane changing maneuvers is more complicated than the calculation of thenminimum safety spacing for a longitudinal vehicle following since, innthe former case we have to take into account the particularnlane-changing policy of the merging vehicle as well as the effect ofncombined lateral/longitudinal motion during the lane changing maneuver.nThe braking profiles of the vehicles involved in an emergency scenarionduring a lane changing maneuver depends on the particular AHSnoperational concept, i.e., on the degree of communication between thenvehicles and between the vehicles and the infrastructure. We considernsix different AHS operational concepts; for each concept we considernpossible emergency braking profiles and we investigate the effect of thenparticular operational concept on the MSSLC