Traffic Flow Patterns
Overview
Section titled “Overview”What are Traffic Flow Patterns?
Section titled “What are Traffic Flow Patterns?”Traffic flow patterns in HDM5 are used to represent the varying traffic intensities that occur on a road throughout a year. They estimate hourly traffic flow levels from Annual Average Daily Traffic (AADT) data to perform congestion analysis. They perform the same purpose as those in HDM-4.
Why are they important?
Section titled “Why are they important?”By dividing the total annual hours into specific groupings, the system can model the impacts of congestion and traffic interactions on both vehicle performance and road agency costs.
Define and edit a Traffic Flow Pattern
Section titled “Define and edit a Traffic Flow Pattern”HDM5 automatically imports all published global Traffic Flow Patterns into an analysis upon creation of that analysis. Edit, delete or create additional patterns these within the analysis.
Attributes
Section titled “Attributes”Traffic flow patterns are defined by a set of flow periods that represent hours of the day (over the course of a 365-day year) with similar traffic intensities.
- Total Hours: The sum of the number of hours in each flow-frequency period must equal 8,760 hours (365 days x 24 hours).
- Period Attributes: For each period, the user specifies the number of hours it occupies per year and the amount of traffic occurring during that time, expressed as a percentage of AADT.