Abstract
The 2010-12 CHTS, which resulted from a statewide, collaborative effort, enabled the collection of travel information from 42,560 Californian households. This rich dataset has helped update regional and statewide travel and will help update environmental models.In 2014, the Institute of Transportation Studies at Irvine (ITS) and Caltrans initiated the “Enhancing the Value of the 2010-12 California Household Travel Survey (CHTS)” contract. This contract was motivated by the idea that potential value of the CHTS is not always well understood by Caltrans staff and that some Caltrans staff from the Office of Travel Forecasting and Analysis may benefit from updating their knowledge of statistical modeling to comfortably query CHTS data and to estimate some common transportation econometrics models.This report provides numerous examples of how to perform various types of statistical analysis on the CHTS. In chapter 2, we discuss the R language and environment for statistical analysis, which was chosen as the primary analysis tool for this project. The following chapters provide specific examples of statistical analysis taken from the contract tasks. In all cases, the actual R code used to perform the analysis is provided, along with detailed discussion of the methods imployed. Chapter 3 describes the Task 1 diagnostic review of the CHTS. In chapter 4, we demonstrate the computation of statistical weights for various subpopulations in the CHTS—a critical component of any analysis involving the CHTS. In chapter 5, we cover the creation of a “linked trip” dataset, which provides a means for analyzing CHTS data in a manner that is compatible with conventional 4-step, trip based models. In chapter 6, we describe the creation of CHTS summary tables generated as part of task 3 work. Finally, chapter 7 describes the solution of a number of statistical queries that were answered under task 4 statistical support tasks.