The following papers and reports are provided for informational purposes only, as a reference regarding how certain procedures were developed. Some of the information contained in these papers may be outdated. Always use the latest version of the APM for current procedures.
Clarification of V/C Ratio Calculation
This paper clarifies methodology and parameters used to calculate volume to capacity (v/c) ratios to compare to the Oregon Highway Plan (OHP) and Highway Design Manual (HDM) mobility standards.
Use of v/c Ratio vs. Delay for Planning and Design Decisions for Signalized Intersections
This paper presents a comparison of the use of volume/capacity (v/c) ratio versus delay for signalized intersections, and recommends a method that should be used for planning and design decisions.
Updated Roundabout Analysis Methodology
This methodology paper presents a comparison of several different roundabout analysis methodologies and recommends a method that should be used by the Department.
Storage Estimates for Unsignalized Intersections
This paper presents a comparison of different methods to estimate queue lengths at unsignalized intersections, and recommends a method that should be used by the Department.
Use of Short-term Interval Counts to Determine K Factors
This paper clarifies the traffic count procedures that should be used to determine the K Factor. Data and calculations used in the study can be found in the table KFactorSummary.pdf.
Network Capacity Calculation for Area Type
This 1997 report attempts to make correlations between the travel demand modeling area type parameter and saturation flow. This is also the background report behind the decision to use 1800 pcphgpl as the ideal saturation flow rate.
The following papers and reports are provided for informational purposes only, as a reference regarding how certain procedures were developed. Some of the information contained in these papers may be outdated. Always use the latest version of the 