Guidelines for Implementing Special Traffic Lanes Passing Lanes and Climbing Lanes

Abstract

Currently, the Department of Highways is responsible for a national highway network totaling 52,341.80 kilometers. The majority of these roads remain two-lane highways, which frequently experience traffic congestion and a high incidence of road accidents, particularly in areas with challenging topography such as steep slopes and sharp curves. In addition, budgetary constraints often hinder the expansion of road capacity through conventional widening methods.

These challenges significantly impact the efficiency and safety of Thailand’s road transportation system. As a strategic response, the Department of Highways has developed the concept of special traffic lanes, which include passing Lanes and climbing Lanes. These special lanes are designed to enhance road safety and improve traffic flow, especially on two-lane highways where overtaking is difficult, particularly for heavy vehicles.

In this study, the research team collected and analyzed key criteria for evaluating the suitability of highway segments for special lane implementation. These criteria include physical road characteristics, traffic volumes, the proportion of heavy vehicles, and roadway gradients. Furthermore, a Level of Service (LOS) analysis was conducted to identify candidate routes that meet the required thresholds. The selected routes will then be prioritized for the design and construction of special lanes with the aim of reducing congestion, improving travel speeds, and enhancing overall road safety for all users.