Technical Appendix 15 SANDAG Travel Demand Model Documentation Appendix Contents SANDAG Travel Demand Model Documentation ............................ TA 15-2 2050 Regional Transportation Plan SANDAG Travel Demand . SANDAG Transportation Model Sensitivity Model Documentation Analysis and Report: This report provides insight into the sensitivity and elasticity of Technical Appendix 15 includes several the SANDAG four-step travel demand reports that document the SANDAG Travel model in terms of policy and operational Demand Model, as follows: adjustment. 2050 Regional Travel Demand Model Documentation: This report presents a description of the components of the SANDAG travel demand model used in the 2050 Regional Transportation Plan, including a general flow of information and some of the key inputs, assumptions, and computations for each of the components. SANDAG Off-Model Greenhouse Gas Reduction Methodology for the 2050 Regional Transportation Plan: This paper documents the SANDAG methodology for estimating the off-model greenhouse gas (GHG) reductions for several strategies included in the 2050 Regional Transportation Plan (RTP). These strategies include aspects of the bicycle, pedestrian, safe routes to schools, vanpool, carpool, and buspool programs. SANDAG Travel Demand Model Validation Report: This report provides a guide to the accuracy of the SANDAG transportation model compared to observed data in and around 2008. It also provides detailed technical information on how the transportation model was used to support the development and decision-making process for the 2050 RTP and its Sustainable Communities Strategy, and the Programmatic Environmental Impact Report. TA 15-2 Technical Appendix 15: SANDAG Travel Demand Model Documentation 2050 REGIONAL TRAVEL DEMAND MODEL DOCUMENTATION SEPTEMBER 2011 401 B Street, Suite 800 • San Diego, CA 92101-4231 • (619) 699-1900 ABSTRACT TITLE: 2050 Regional Travel Demand Model Documentation AUTHOR: San Diego Association of Governments DATE: September 2011 SOURCE OF San Diego Association of Governments COPIES: 401 B Street, Suite 800 San Diego, CA 92101 (619) 699-1900 NUMBER OF 63 PAGES: ABSTRACT: The SANDAG regional travel demand model comprises a complex set of assumptions, input data, computations, and model interactions. This report presents a basic description of the components of the SANDAG travel demand model used in the 2050 Regional Transportation Plan, including a general flow of information and some of the key inputs, assumptions, and computations for each of the components. i TABLE OF CONTENTS EXECUTIVE SUMMARY ................................................................................................................. 1 CHAPTER 1: GROWTH FORECAST BACKGROUND ........................................................................ 3 1.1 OVERVIEW ........................................................................................................................ 3 1.2 DEMOGRAPHIC AND ECONOMIC FORECASTING MODEL (DEFM) .................................. 5 1.3 INTERREGIONAL COMMUTE MODEL (IRCM) ................................................................... 5 1.4 URBAN DEVELOPMENT MODEL (UDM) ............................................................................ 6 1.5 POPULATION BY AGE, SEX, AND ETHNICITY FORECAST (PASEF) ................................... 6 1.6 DATA SOURCES................................................................................................................. 7 CHAPTER 2: TRANSPORTATION MODELS ..................................................................................... 8 2.1 INTRODUCTION ................................................................................................................. 8 2.2 SURVEY INPUTS .............................................................................................................. 11 2.2.1 1995 & 2006 Travel Behavior Surveys ............................................................................................. 12 2.2.2 2001 Caltrans Statewide Survey & 2009 National Household Travel Survey ............................. 12 2.2.3 2001-2003 & 2009 Regional Transit Survey .................................................................................... 12 2.2.4 External Trip Surveys ......................................................................................................................... 13 2.2.5 Traffic Generator Studies ................................................................................................................. 13 2.2.6 1991 Visitor Survey ............................................................................................................................ 13 2.2.7 Census Transportation Planning Package and American Community Survey ........................... 13 2.2.8 2000 Market Research Survey .......................................................................................................... 14 2.2.9 Traffic Counts ..................................................................................................................................... 14 2.2.10 Transit Passenger Counts .................................................................................................................. 14 2.2.11 2006 Vehicle Occupancy and Classification Study ......................................................................... 15 2.3 GROWTH FORECAST INPUTS ........................................................................................... 15 2.4 HIGHWAY NETWORK INPUTS ......................................................................................... 16 2.4.1 Highway Facilities .............................................................................................................................. 17 2.4.2 Highway Attributes ........................................................................................................................... 17 2.4.3 Highway Capacities ........................................................................................................................... 18 2.4.4 Highway Travel Times ....................................................................................................................... 20 2.5 TRANSIT NETWORK INPUTS ............................................................................................ 20 2.5.1 Transit Facilities ................................................................................................................................. 21 2.5.2 Transit Attributes .............................................................................................................................. 21 2.5.3 Travel Times ....................................................................................................................................... 22 2.5.4 Fares .................................................................................................................................................... 23 2.5.5 Transit Walk Access ........................................................................................................................... 23 ii 2.5.6 Transit Auto Access ........................................................................................................................... 24 2.6 TRIP GENERATION .......................................................................................................... 25 2.6.1 Model Structure ................................................................................................................................. 26 2.6.2 Model Calibration ............................................................................................................................. 29 2.7 PATHBUILDING, SKIMMING, AND UTILITY CALCULATIONS .......................................... 29 2.8 TRIP DISTRIBUTION ......................................................................................................... 31 2.8.1 Model Structure ................................................................................................................................. 32 2.8.2 Model Calibration ............................................................................................................................. 35 2.9 MODE CHOICE................................................................................................................. 35 2.9.1 Model Structure ................................................................................................................................. 37 2.9.2 Utility Computations ......................................................................................................................... 40 2.9.3 Model Calibration ............................................................................................................................. 50 2.9.4 Mode choice variations..................................................................................................................... 50 2.10 TRUCK MODEL .................................................................................................................... 51 2.10.1 Model Design ..................................................................................................................................... 51 2.10.2 Local Truck Model ............................................................................................................................. 52 2.10.3 Regional Truck Model ......................................................................................................................