Establishment of a Road Classification System and Geometric Design and Maintenance Standards for Low-Volume Roads

Abstract

The primary purpose of a road hierarchy is to ensure that appropriate management, engineering standards, and maintenance practices are applied to a road on the basis of its function. A hierarchy also enables more efficient use of limited resources by allocating funds to those roads that are in greater need and for which the costs are better justified. Studies were recently completed to arrive at a classification system for a wide range of low-volume roads covering rural municipalities and forestry organizations. Results are presented of an extensive literature search and the process and methodology developed to arrive at acceptable standards for various stakeholders relative to a classification system and geometric design and maintenance standards for low-volume roads. Five road classifications are derived for low-volume roads, including functional and road characteristics, to assist in classifying each road in a network. Also included for each road class are guidelines for geometric standards that relate to design speed, cross-sectional elements, and horizontal and vertical curve requirements for flat, hilly, and mountainous terrain. These standards were derived with reference to existing standards, engineering experience, and resources available to a road agency. Each classification has a set of maintenance criteria for both sealed and unsealed roads, covering the key defect types and intervention levels for routine and urgent maintenance.