Reliability and Quality of Service Evaluation Methods for Rural Highways: A Guide (2024)
Chapter: 5 HCM7 Automobile LOS Methodologies
CHAPTER 5
HCM7 Automobile LOS Methodologies
This part of the Guide provides an overview of the existing HCM7 analysis methods that are used in the rural highway LOS methodology for automobiles. Those analysis methodologies are as follows:
- Multilane highways.
- Two-lane highways.
- Signalized intersections.
- Roundabout intersections.
- AWSC intersections.
- Urban streets.
This part also contains a consolidated overview of the applicable analysis methodologies within the HCM7 for bicycle operations on rural highways.
This part of the Guide is not intended to duplicate in full the analysis methodology material provided in the HCM, but rather to provide a concise summary of the applicable equations and exhibits for each analysis methodology used in the rural highway LOS methodology. The specific equation and exhibit numbers used in the respective methodology are presented in the general order in which they are applied. All equation variable definitions are included in a nomenclature section at the end of each methodology chapter.
In addition, any simplifying assumptions from or revisions to the HCM7 methodologies are described in the corresponding methodology sections. The methodology simplifications or revisions are identified in a shaded box, for example:
Methodology Simplification
This step is simplified by. . .
Methodology Revision
This methodology is revised by. . .
Note that the analysis methodology is direction-specific. That is, results are specific to a single direction. For some roadway configurations, information about other directions of travel (traffic, roadway, control) may be needed to determine the operational quality for the analysis direction of travel. For example, for a two-lane highway passing zone, it is necessary to know the traffic volume in the opposing direction. Likewise, for intersections, such as roundabouts and AWSC, traffic operations on a given approach are affected by traffic demands and lane configurations on other approaches.
