Using immersive virtual reality to evaluate pedestrian street crossing decisions at a roundabout

In this paper, we use an immersive virtual environment to assess the separation, or "gap," between moving vehicles that people need before initiating a street crossing in a roundabout, where traffic can be approaching from several directions. From a pedestrians viewpoint, crossing at a roundabout can represent a more complex decision than at a normal linear intersection. This paper presents the design of a system that simulates reasonable traffic patterns that a pedestrian might encounter in making a crossing decision at the exit lane of a roundabout, while controlling the gap duration in the stream of traffic. Using a maximum-likelihood procedure, we conducted a street crossing experiment in the virtual environment to evaluate the minimum gap during which pedestrians would initiate a successful crossing of the intersection. Our results are generally consistent with real-world data on pedestrian street crossings, and may provide insights into how to engineer the design of such roundabouts.