Institute of Transportation, MOTC

Two-lane highways have only one lane in each direction capable of accommodating passenger cars and large vehicles. Passing vehicles on such highways have to utilize opposing lanes. Because of rough terrains, the rural two-lane highways in Taiwan often have steep grades and sharp horizontal curves and thus have complex traffic operating characteristics. Even if a large amount of field data is available, it is difficult to develop reliable analytical tools for analyzing this type of highways. Consequently, many countries have resorted to the development and use of simulation models to facilitate planning, design, and assessment of improvement strategies. The 2016 Highway Traffic Systems Simulation (2016HTSS) model developed by the Institute of Transportation (IOT), Ministry of Transportation and Communications, can reasonably simulate the traffic operations of Taiwan’s rural two-lane highways. This paper presents the likely speed-flow relationships on straight and level segments of Taiwan’s rural highways, discusses the nature of passing behavior and its simulation, explores the representative vehicles suitable for design and analysis of the grade segments on Taiwan’s rural two-lane highways, and illustrates the applications of the 2016HTSS model.