Collecting activity-travel diary data : state of the art and a hand-held computer-assisted solution Bruno Kochan, Tom Bellemans, Davy Janssens, Geert Wets Transportation Research Institute (IMOB) Hasselt University Belgium Universiteit Hasselt, Campus Diepenbeek, Wetenschapspark 5 bus 6, BE-3590 Diepenbeek, Belgium

Introduction to Activity Based (AB) data Data collection Functional description of a new data collection tool Conclusion Outline

1950: - Rapid increase in need for transportation - Several Transportation models were used to predict travel demand Four-step models: Travel = result of 4 subsequent decisions, modelled separately Disadvantage of four-step models: No relationship travel non-travel aspects Introduction Solution: Activity-Based (AB) transportation models

AB models predict interdependencies between several facets of activities Facets: Introduction - Which type of activity ? - When ? - For how long ? - Conducted where ? - Which transport mode ? - With whom ?

Data is collected by means of Activity-Travel diaries Diary consists of a sequence of activities and journeys Diary focuses on all the activities and journeys Diaries: - Take time to fill out - A lot of activity facets Data Collection Activity Based transportation models: Heavy demands on data collection system

Data Collection Paper-and-pencil + Con: - Prone to errors - Complex Pro: -Filled out any time and place - Consistency - Tedious

Data Collection Computer aided self interview of activity-travel scheduling behaviour: - CHASE (Doherty, 1997) - VIRGIL (UHasselt, 2004) Pro: - Data quality - User guidance Con: - Filled out at specific time - Filled out at specific place - Portability

Data quality: - Activity: e.g. Begin time before end time - Activity and Journey: “Location continuity” - Activity and Journey: No time gaps - Journey: e.g. Duration journey must equal sum trip durations Data Quality

Activity 1 Location A Activity 2 Location B Journey 1 Start Location A Start Location B

Data Quality Activity 1 Location A Activity 2 Location B Journey 1 Start Location A Start Location B

Data Quality Activity 1 Location A Activity 2 Location B Journey 1 Start Location A End Location C !

Data Quality Activity 1 Location A Activity 2 Location B Journey 1 Start Location A End Location B

Data Collection Computer-aided self interview of activity-travel scheduling behaviour: - CHASE (Doherty, 1997) - VIRGIL (UHasselt, 2004) Pro: - Data quality - User guidance Con: - Filled out at specific time - Filled out at specific place - Portability

Data Collection Internet-based self interview of activity-travel scheduling behaviour: - iCHASE (Doherty, 1999) - REACT (McNally, ) Pro: - Filled out at different times - Filled out at different places (e.g. work, home) - Portability

Personal Digital Assistant (PDA) Data Collection - EX-ACT (Rindsfüser, 2003) Pro: - Filled out at any time - Filled out at any place (e.g. work, home, bus) Con: - Battery autonomy

GPS-enabled Personal Digital Assistant (PDA) Data Collection - Doherty, 2001 Pro: - Respondent may forget to report journey - Data can be used for checking consistency - Enables capturing route information Con: - GPS not always reliable - GPS accuracy (±30m) - IMOB, 2005

- “Multipath” GPS not always reliable: Disadvantages GPS

GPS accuracy: - Sattelites geometry Disadvantages GPS

GPS accuracy: - Time spent on measurement Disadvantages GPS - Start location - End location

Autonomy: Disadvantages GPS

GPS Logger GUI AB Survey GIS Module Data Integrity Checks Trip Identification Communication Module GPS Data Activity Diary & Household Data GUI Household Survey Functional description of a new data collection tool

GPS Logger GUI AB Survey GIS Module Data Integrity Checks Trip Identification Communication Module GPS Data Activity Diary & Household Data GUI Household Survey Functional description of a new data collection tool

- Which type of activity ? - When ? - For how long ? - Conducted where ? - With whom ? Activity attributes: Functional description of a new data collection tool

Conclusion Different approaches and technology for AB data collection Data collection tool for a GPS enabled PDA