What is Highway Capacity Manual Volume 4?
The HCM includes three printed volumes (Volumes 1-3) that can be purchased from the Transportation Research Board in print and electronic formats. Volume 4 is a free online resource that supports the rest of the manual. It includes:
- Supplemental chapters 25-38, providing additional details of the methodologies described in the Volume 1-3 chapters, example problems, and other resources;
- A technical reference library providing access to a significant portion of the research supporting HCM methods;
- Two applications guides demonstrating how the HCM can be applied to planning-level analysis and a variety of traffic operations applications;
- Interpretations, updates, and errata for the HCM (as they are developed);
- A discussion forum allowing HCM users to ask questions and collaborate on HCM-related matters; and
- Notifications of chapter updates, active discussions, and more via an optional e-mail notification feature.
Who Can Access HCM Volume 4?
HCM Volume 4 is free to everyone, but registration is required. Sign up now to take advantage of these resources and join the discussion!
