Highway Capacity Manual (6th Edition): A Guide for Multimodal Mobility Analysis – Volume 1,2,3

Introduction

The Highway Capacity Manual (HCM) is an essential resource for transportation professionals and engineers involved in analyzing and planning transportation systems. Published by the Transportation Research Board (TRB) of the National Academies, the HCM provides a comprehensive guide to assess the capacity and performance of various transportation modes, including highways, streets, bicycles, pedestrians, and transit. The HCM’s latest edition, the 6th Edition, consists of three volumes that cover a wide range of topics related to multimodal mobility analysis. In this blog post, we will explore each volume and highlight the key features and benefits it offers.

Volume 1: Concepts

Volume 1 of the Highway Capacity Manual serves as an introduction to the fundamental concepts and methodologies used in transportation analysis. It covers the basic principles of capacity, level of service, and performance measures. This volume lays the foundation for understanding the subsequent volumes and provides a common language for transportation professionals to communicate effectively.

One of the significant updates in Volume 1 is the inclusion of multimodal analysis. With the growing emphasis on sustainable and integrated transportation systems, the HCM addresses the need to evaluate the performance of various modes simultaneously. This volume presents methods to quantify multimodal operations and evaluate their interactions. It includes methodologies for assessing performance measures, such as person delay and accessibility, across different modes.

Volume 2: Uninterrupted Flow

Volume 2 of the HCM focuses on the analysis of uninterrupted flow facilities, such as freeways and multilane highways. It provides detailed procedures for estimating capacity, level of service, and queue lengths in various operational conditions. This volume covers topics like freeway facilities, basic freeway segments, freeway weaving segments, and freeway merging and diverging segments.

The 6th Edition of the HCM introduces several significant updates to Volume 2. It incorporates new methodologies to assess the performance of managed lanes, including high-occupancy vehicle (HOV) lanes and express toll lanes. Additionally, it includes revised methodologies for analyzing heavy vehicles, work zones, and oversaturated conditions. These updates ensure that transportation professionals have the most accurate tools and techniques to evaluate and plan for uninterrupted flow facilities.

Volume 3: Interrupted Flow

Volume 3 of the HCM addresses the analysis of interrupted flow facilities, such as signalized intersections, roundabouts, and urban streets. This volume provides comprehensive guidance on estimating capacity, delay, and level of service for different intersection types and operational conditions. It covers a broad range of topics, including signalized intersections, unsignalized intersections, roundabouts, and urban streets.

The 6th Edition of the HCM brings several significant updates to Volume 3 to reflect the latest research and best practices in analyzing interrupted flow facilities. It introduces new methodologies for evaluating bicycle and pedestrian facilities, taking into account their unique characteristics and interactions with vehicular traffic. The volume also presents improved methodologies for assessing transit facilities, including bus stops and transit signal priority. These updates ensure that transportation professionals can accurately analyze and design urban streets and intersections to accommodate all modes of transportation.

Conclusion

The Highway Capacity Manual (6th Edition) is an invaluable resource for transportation professionals and engineers engaged in multimodal mobility analysis. The three volumes of the HCM provide comprehensive guidance on assessing the capacity and performance of highways, streets, bicycles, pedestrians, and transit. The inclusion of multimodal analysis in the latest edition reflects the increasing importance of integrated transportation systems.

Whether you are evaluating uninterrupted flow facilities like freeways or analyzing interrupted flow facilities such as signalized intersections, the HCM offers detailed methodologies and procedures to assess the performance of these facilities accurately. The updates in the 6th Edition ensure that transportation professionals have

the most up-to-date tools and techniques to plan and design efficient and sustainable transportation systems. By leveraging the insights and methodologies presented in the Highway Capacity Manual, transportation professionals can make informed decisions, improve mobility, reduce congestion, and create transportation networks that meet the needs of diverse users. The HCM remains an indispensable resource for anyone involved in transportation analysis and planning, shaping the future of our multimodal transportation systems.