Study on Driver Gaze Characteristics in Sight Distance Limited Section of Mountain Highway Based on Visual Information

In order to study the gaze behavior characteristics of drivers in mountainous road sections with limited sight distance, the real vehicle test is carried out by using Smart Eye Pro 5.7 noninvasive eye tracker. Combined with the sight distance change rate theory, 6 typical test representative mountainous sections are selected to study the gaze distribution law and gaze duration of drivers in different mountainous sections. The research shows that when the driver drives on the test section with the most unfavorable sight distance of 44 m, 50 m, and 56 m, the fixation characteristics of “from far to near” are significant, and the long fixation duration accounts for a large proportion of the driver. When the driver drives on the section with the most unfavorable sight distance of more than 70 m, i.e., the sight distance change rate of less than 1.33, the fixation characteristics of “from far to near” disappear. The driver’s fixation stability increases, the fixation freedom increases, and the proportion of medium and long fixation duration decreases. The data analysis provides a theoretical basis for drivers to pass safely in mountainous sections.

Modeling Urban Road Scenarios to Evaluate Intersection Visibility

Road safety is key to sustainable mobility. Rapid technological advances have allowed several road safety-related analyses, previously performed in situ, to be conducted virtually. These virtual analyses benefit understanding of how roads operate and how users perceive them. Additionally, they facilitate the assessment of several parameters that are fundamental to road design and operation. The available sight distance (ASD) is one of these parameters that, if not provided adequately, could alter the proper functioning of roads. This study presents a framework to assess the impact of certain features on visibility. First, the ASD is estimated using a geographic information system (GIS)-based procedure with LiDAR-derived three-dimensional (3D) models. Afterward, obstructions are detected and categorized. If the obstruction cannot be removed, their redesign or relocation is simulated to re-run the analysis. These simulations are performed using 3D city objects, and their results are statistically evaluated, providing evidence as to their effects on visibility. The results proved that the procedure helped achieve the efficient use of roadside space, while including safety concerns. Additionally, this study reflects the need for more inspections on the impact of on-street parking on drivers’ fields of view.

Coupling Impacts of Spray and Rainfall on Road Visibility and Vehicle Speeds: A Simulation-based Analysis

Impaired visibility resulting from rainfall contributes greatly to the occurrence of traffic accidents. This study presents a numerical simulation approach to analyze the extent to which the coupling of spray and raindrops reduces visibility and thus proposes safe speeds against inadequate visibility. The spray-raindrop coupling particles were modeled by considering the real highway design parameters and rainfall conditions. The road visibility was estimated through simulating the multiple scattering process of taillights in the spray-rain medium, and the maximum safe speed against inadequate visibility was then derived by comparing the visibility with the required stopping sight distance. Results show that: 1) either a high speed of the front truck or a thick water-film results in a significant reduction in road visibility and the maximum safe speed of the ego vehicle, 2) front vehicle speed plays a more important role in visibility reduction than the water-film thickness does.

Strategic planning of transportation infrastructure networks with case studies

This paper discusses necessary qualitative and quantitative improvements in transport infrastructure networks and analyzes travel behavior and origin-destination situations. This paper studies idea about the re-planning of transportation infrastructures theoretically and implements a case study strategy that applies the gravity model and graph technique. Additionally, it has a mathematical model that assists in designing traffic flow in new streets, sidewalks, plazas, and spaces, while suggesting new urban land-use policies and transportation infrastructure-locating techniques. This work considers the planning of ground, railroad, maritime, and air transportation to build a comprehensive system in the urban master planning process. It prioritizes public transportation and suggests necessary geometrical adjustments to upgrade the situation of the infrastructure and prepare Chabahar city for its strategic and oceanic role. The outcome in geometric corrections in sight distance and transverse and longitudinal curves in streets, sidewalks, and squares will assist cities in the Silk Road project environmentally and make the region attractive to tourists and investors' eyes.

3D Sight Distance Calculation and Estimation of its Effect on Road Accidents in GIS Environment

Nowadays, one of the main causes of human death is driving accidents. Across the world 1.2 million people die and several million people get injured annually as a result of road accidents. One of the main solutions that is important in resolving the problem of accidents is identifying the factors and their role and impact and the contribution of each in the accident. The stopping sight distance in the route is one of the initial factors in the driver’s performance error as well as the occurrence of an accident, financial losses, and deaths. The geometric design of roads is generally designed according to two-dimensional rules and regulations. Hence, today, given the remarkable advances in computer science and programming, there are many possibilities for 3D modeling of the route. Therefore, the calculation of the stopping sight distance should be based on existing facts and new scientific achievements. On the contrary, the stopping sight distance is one of the factors affecting driving crashes; therefore, this paper tries to investigate the accident occurrence probability in other spots of the existing route by calculating 3D stopping sight distance and using drivers’ free flow speed, as well as using the GIS software. In this way, the results of this study can pave the way for improving the geometric design of existing roads as well as prioritizing the correction of the accidental points of existing routes.