Publication Detail

Estimation of Allocation Factors of Travel Demand Model Volumes to Hourly Volumes for Highways in the South Coast Air Basin

UCD-ITS-RR-99-12

Research Report

Suggested Citation:
Niemeier, Debbie A., S. Kim, J. Hicks, M. Korve (1999) Estimation of Allocation Factors of Travel Demand Model Volumes to Hourly Volumes for Highways in the South Coast Air Basin. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-99-12

This report is divided into 6 chapters. In Chapter 2, a review of the data that has been collected from Los Angeles and San Diego is presented. The data include both real-time traffic volumes and travel demand model link volumes. We also present digital maps displaying the San Diego and Los Angeles freeway networks and traffic counter locations. Chapter 3 describes how each of the daily real-time traffic data files were categorized based on the temporal proximity to the ozone episodes that occurred over the summer of 1997 in the South Coast region. An exploratory analysis of the data in relation to these ozone episodes is also presented. Chapter 4 explains how the average daily traffic patterns vary between counter locations and discusses the statistical analysis used to cluster each location into the category which best represents its daily hourly pattern. This analysis was done separately for the San Diego and Los Angeles data sets. Chapter 5 provides an in-depth discussion of the computation of the allocation factors, which disaggregate the period-based model volumes into hour-based volumes. Finally, Chapter 6 provides the framework for how the results can be applied. There is also an appendix with the SAS code for computing clusters and allocation factors.