M L1

• Previous lectures (Prof. Karst Geurs): travel behaviour
• Why do people travel?

  Complexity of choice behaviour, different perspectives (Psychological, Economic, Geographical)
• How do we model all this? And why do we need models?
• An overview of transportation models and applications
• These concepts are needed for your Project!
• Model


  • Simplified image of part of reality
  • Transportation model describes human behaviour based on a theory
  • Theory describes connections between the variables of the model
• Exogenous variables


  Independent or explanatory variables
• Endogenous variables


  Dependent or "to be explained" variables
• Car ownership


  f(economic growth)
• Correlation between these variables is represented with mathematical formulas</b>
• Coefficients


  Value of exogenous affects the value of endogenous
• Determining the coefficients


  Statistical estimation (from empirical data)
• Travel model


  Analysis tool that provides a systematic framework for representing how travel demand changes in response to different input assumptions
• Travel model


  • Comprehensive: regional, municipal (what activities, where and when they occur and how people get to them)
  • Limited in scope: e.g. airport-related travel, travel within a corridor, or a district in the city
• Travel demand modeling/forecasting


  Number of persons/ vehicles expected to travel between a particular ORIGIN and DESTINATION via a particular ROUTE and MODE of travel over a given TIME period
• A model is not a "crystal ball" for predicting the future, but rather a tool for estimating effects of changes in input assumptions and policy measures
• Types of transportation models and applications

  • Descriptive
  • Exploratory
  • Spatial
  • Non-Spatial
  • Aggregated
  • Disaggregated
  • Static
  • Dynamic
  • Revealed preference
  • Stated-choice preference
  • Travel
  • Activities
• Descriptive models


  • Represent correlations between variables without explicitly considering causality
  • Quantitatively describes or summarizes characteristics of information
  • Rigid
• Exploratory models


  • Map out causes and consequences
  • Discoveries of ideas and thoughts
  • Flexible
• Example


  • Descriptive: Trips/HH divided by Persons/HH = number of trips/person
  • Exploratory: Run a multiple regression model to describe trips/hh in relation to income, number of persons/hh and hh/area
• Spatial models


  Location of activities in space is an explicit component in the model
• Non-spatial models


  Physical space does not play a role
• Example spatial model


  • Research area divided in zones
  • Networks of transport modes
  • Establish origin-destination matrices = number of trips per transport mode between every pair of zones
• • Aggregated: Unit of observation: zone, neighbourhood, etc
  • Origin 1950's
  • Paradigm: Predict and provide
  • Build roads indefinitely
• • Disaggregated: Unit of observation: individual
  • Origin 1970's
  • Paradigm: Predict and prevent
  • Containing measures
  • Promoting alternatives for car
  • Optimal use of existing infrastructure
  • Limited building of new infrastructure
  • Progress of statistical estimation
  • Individual variation instead of zone averages
  • Aggregated before making forecasting
  • Interest is in the aggregated traffic flows on the roads and PT, and not on the mobility of one individual
• Static models


  • Behaviour analyzed in specific point in time
  • Cross-section data
• Dynamic models


  • Changes in behaviour analyzed over time
  • Time-series data (panel)
• Example dynamic model


  • Current year (short, medium, long vacations)
  • Last year (short, medium, long vacations)
  • 2 years ago (short, medium, long vacations)
  • TOTAL OF 9 LAGGED VARIABLES
• Revealed preference


  • Real situation, actual behaviour
  • eg travel diary, mobility survey
• Stated-choice preference


  • Hypothetical situation
  • eg SC experiment
• Travel models


  • Based on trips
  • Trips are Independent
  • Simpler description of the behaviour
  • Simple, Cheaper
• Activity models


  • Based on a schedule, tour, or "trip-chain"
  • Trips are Dependent
  • Better description of behaviour
  • Complex, expensive
• The land-use transport feedback cycle
• Transport and land use interactions
• The 4-Step Transport Model, The Classic Transport Model, The 4-step Travel Demand Model

  1. Originally developed in the 1950's when planning major highway facilities

  2. Importance of location of origins and potential destinations for travel behaviour

  3. Four decisions are the basis of the traditional TDM: The choice and reason to travel, The destination to travel to, The mode by which to travel, The route on which to travel
• Example of a trip-based model

  • Home-based work (HBW)
  • Home-based shop (HBS)
  • Home-based other (HBO)
  • Non-home based (NHB)
• Urban transport modeling system
• Trip generation questions


  • How many trips will be generated by a given location?
  • When will these trips occur?
  • For what purpose do people use the transport system?
• Trip distribution questions


  Given a location, where do people go to satisfy the demand for an activity type?
• Mode choice questions


  • How do people use the transport system?
  • What modes do they choose?
  • How do they react to varying service quality of the transport modes?