Assessment of intersection conflicts between riders and pedestrians using a GIS-based framework and portable LiDAR

Resumen

Adequate sight distances are crucial parameters ruling the design of roads and riding facilities. LiDAR-retrieved data have proved to serve many transportation applications by creating updated and accurate representations of the road environment. As a result, many sight distance evaluation methodologies use LiDAR delivered point clouds to carry out visibility analyses. However, current approaches are mainly focused on motorized users along highways and streets, and most of those methodologies are carried out directly on the point cloud, which does not allow the evaluation or relocation of visual obstructions. This study presents a visibility-based procedure intended to assess the circulation of pedestrians and riders at urban intersections. For this purpose, first, the required sight distances of all users along the intersection are obtained. Second, the conflicts between vulnerable road users are evaluated, considering the type of control present at the intersection. The available sight distances are then obtained using a GIS-based method that employs 3D road models derived from the LiDAR retrieved data. Finally, after a comparison between the required and the available visibility, an evaluation determines which user sees a larger percentage of the intersection. This approach facilitates evaluating the impact that vegetation, traffic, and/or furniture elements could have on visibility and serve as an urban design aid tool. Results show that the proposed method offers valuable insights into the distributions of visibility among intersecting users and into the quantifications of the effect of specific adjacent traffic. Moreover, this procedure stands as a useful and flexible approach that allows the evaluation of both cyclists and e-scooter riders in different road facilities and positionings.