Abstract: With the widespread development and testing of autonomous driving technology, the safe operation of autonomous vehicles (AVs) is now on the research agenda. Due to the limited sight line on freeway entrance terminals, crashes involving AVs continue to occur during the merging operation. The AV’s operational design domain (ODD) defines the conditions in which its driving automation system is designed to function. No studies, however, have explored ODD quantification in freeway entrance terminals. This study therefore quantified the ODD for AV sensors in freeway entrance terminals with flat grades and 5% grades separately, based on sight triangle requirements. Required stopping sight distance (SSD) for the merging AV and travelled distance of the mainline vehicle were calculated based on vehicle kinematics, and required detecting range and detecting angle for AV sensors were calculated as the ODD constraint indicators at various design speed combinations of ramp and mainline, based on the law of cosines. Two merging section types, the taper and the parallel, are considered. Results show: 1) the required detecting range has minor differences between the taper and parallel sections; 2) the required detecting range increases with design speeds of both ramp and mainline, while required detecting angle decreases with increasing ramp design speed; 3) required SSD, travelled distance of the mainline vehicle, and required detecting range on sections with downgrades are larger than those with flat grades, while those with upgrades are smaller than flat grades.
Xinchen Ye, Xuesong Wang*. Operational Design Domain of Autonomous Vehicles in Merging Sections of Freeway Entrance Terminals. Transportation Research Board 101th Annual Meeting, Washington D.C., USA, 2022. 1.9-13.