Evaluation of Safety in Horizontal Curves of Roads Using a Multi-Body Dynamic Simulation Process

Abstract

Road transportation poses one of the significant public health risks. Several contributors and factors strongly link public health and road safety. The design and advancement of higher-quality roads can significantly contribute to safer roads and save lives. In this article, the safety aspect of the roads’ horizontal curves under the standard of the American Association of State Highway Transportation Officials (AASHTO) is evaluated. Several factors, including vehicle weight, vehicle dimensions, longitudinal grades, and vehicle speed in the geometric design of the horizontal curves, are investigated through a multi-body dynamic simulation process. According to the AASHTO, a combination of simple circular and clothoid transition curves with various longitudinal upgrades and downgrades was designed. Three vehicles were used in this simulation, including a sedan, a bus, and a 3-axle truck. The analysis was based on the lateral friction between the tire and the pavement and also the safety margin parameter. The results showed that designers must differentiate between light and heavy vehicles, especially in curves with a high radius. Evaluation of longitudinal grade impacts indicated that the safety margin decreases when the vehicle is entering the curve. Safety margin reduction on the clothoid curve takes place with a lower grade toward the simple circular curve. By increasing the speed, the difference between lateral friction demand obtained from simulation and lateral friction demand proposed by AASHTO grows. The proposed novel methodology can be used for evaluating road safety.

Why Do Drivers’ Collision Avoidance Maneuvers Tend to Cause SUVs to Sideslip or Rollover on Horizontal Curve and Grade Combinations?—An Analysis of the Causes Based on a Modified Multibody Dynamics Model

“…Please note that this work is only applicable to SUVs. There is evidence that the stability of trucks is significantly lower than that of SUVs [ 55 ]. This may be especially true for tractor–semitrailers that rely solely on saddle articulation and are thus more likely to skid and roll over during steering, pile up, or cause other hazardous conditions due to their large inertia, poor maneuverability, and long wheelbase [ 56 ].…”

Application of Analytical Hierarchy Process for Structural Health Monitoring and Prioritizing Concrete Bridges in Iran

“…Another gap that has been followed in this study is the lack of a comprehensive, practical, scientific method for bridge networks in Iran. Although there are attempts in the field of developing health monitoring methods for various infrastructures in Iran, such as [28][29][30][31][32][33][34][35][36][37]; however, the absence of a full detailed, efficient, specialized method for bridges can be felt. Consequently, the authors also tried to fill the later gap, and therefore, the proposed method is based on the condition of bridges in Iran.…”

Ranking Road Sections Based on MCDM Model: New Improved Fuzzy SWARA (IMF SWARA)

“…Additionally, the dynamic simulation procedure analyzed several factors (longitudinal grades, minimum radius of horizontal curve, vehicle speed, changes in vehicle length and weight, and differences in changes in driver behavior) where the level of traffic safety was determined across large radius curves. This research demonstrates the need for the introduction of clothoid transition curves, and also proposed a methodology for the analysis of lateral friction for speeds of 50, 80, 110, and 130 km/h [18]. At the same time, the analysis of lateral friction, through the reduction of the coefficient of friction by 5% in vertical curves, increased the probability of a traffic accident by 20% for rescue vehicles.…”