Long Distance Travel in Europe Surveying Methods, Data Availability and Comparability

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Long Distance Travel in Europe Surveying
Methods, Data Availability and Comparability
Tobias Kuhnimhof Institute for Transport
Studies, University Karlsruhe INRETS, Paris
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Introduction

• Long distance travel journeys over 100 km
• Long distance travel is a rare event from the
  individual perspective
• Small share of all trips 1
• Large share of travelled mileage
• Motorized modes
• High potential for positive effects of
  behavioural change
• Interregional and international travel is of EU
  interest
• Compilation of EU-wide harmonized statistics on
  long distance travel in KITE project
  www.kite-project.eu

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Relevant Sources for Long Distance Travel Data

• Mobility diaries of national travel surveys
  (usually 1 day, 1 week)
• NTS samples contain long distance trips because
  long distance travel is part of the mobility on
  an average day
• Surveying long distance travel and everyday
  travel with the same instrument
• Advantages
• Internationally standardized survey format
• Problems
• Large sample sizes necessary for sufficient
  sample of LD-journeys
• No individual analysis possible
• Capturing journeys with overnight stays

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Relevant Sources for Long Distance Travel Data

• Special techniques to survey long distance travel
  
• Respondents report over longer periods of time
• Only long distance journeys reported
• Increase journey sample size
• Enable individual analyses identify frequent
  travellers
• More degrees of freedom
• Survey periods from 2 weeks to one year
• Need to define long distance travel for the
  respondents
• Moment of collecting information (prospective,
  retrospective, mixed formats)
• Survey format not standardized

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Relevant Sources for Long Distance Travel Data
Country NTS NTS Elements on Long Distance Travel Long Distance Travel Surveys
Austria 1995 1995 -
Belgium 1998/1999 1998/1999 -
Czech Republik 2000-2003 2000-2003 -
Denmark 2007 - -
Finland 2004/2005 2004/2005 -
France 1993/1994 1993/1994 -
Germany 2006 2002 1999-2002
Greece (1996) - -
Italy 2004/2005 2004/2005 -
Netherlands 2006 - -
Norway 2005 2005 -
Portugal - - 1998
Spain 2000-2002 2000-2002 -
Sweden 2005/2006 2005/2006 -
United Kingdom 2002-2004 2002-2004 -
Switzerland 2005 2005 -
EU-15 CH 2001-2002
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Problems of data comparability

• Surveys differ in
• Population (e.g. age groups)
• Seasonality effects
• Length of reporting period
• ...
• Almost as many definitions of long distance
  travel as surveys exist
• 20 km (Italy) up to 200 km round trip (Belgium)
• 3h excursions (CH), overnight stays (CH, German
  MiD)
• Distances crow-fly, network, reported?
• Impossible to compile harmonized statistics based
  on published figures
• Micro-data analysis necessary

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Discussion of Surveying Techniques

• The Surveys under Scrutiny

Survey Spatial Scope Method Survey Period
DATELINE EU 15 CH Retrospective Telephone/postal 12 months for holiday journeys 3 months for other
SWISS MC Mobility diary Switzerland Retrospectivetelephone 1 day
SWISS MC Excursions Switzerland Retrospectivetelephone 2 weeks
SWISS MC overnight journeys Switzerland Retrospectivetelephone 4 months
GB NTS Mobility diary Great Britain 2 face-to-face interviews 1 week
GB NTS LD travel report Great Britain 2 face-to-face interviews 4 weeks
MiD Mobility Diary Germany Retrospective Telephone (postal) 1 day
MOP Germany 1 week diarypostal 1 week
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Discussion of Surveying Techniques

• Definition of long distance travel used
• Journeys gt 100 km crow-fly distance (DATELINE
  definition)
• Calculation of crow-fly distances from reported
  distances using average detour factors (based on
  DATELINE)
• Germany MID, MOP ? detour factor 1.28
• UK GB NTS ? detour factor 1.22

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Discussion of Surveying Techniques

• Results Number of LD-Journeys per person per
  year

• DATELINE figures clearly below other surveys
  (except Swiss MC excursion/ overnight journey
  questionnaire)
• Results of other surveys quite comparable
• Implausible difference between some countries in
  DATELINE data

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Discussion of Surveying Techniques

• Results Number of LD-Journeys per person per
  year by journey length

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Discussion of Surveying Techniques

• Results Number of LD-Journeys per person per
  year by journey length

Retrospective CATI, 4 months
Retrospective CATI, 2 weeks
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Discussion of Surveying Techniques

• Results Number of LD-Journeys per person per
  year by journey length

Placement interview
Collection interview
mobility diary
3 week LD travel record
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Discussion of Surveying Techniques
Journeys 100 400 km per person per year
Journeys gt 400 km per person per year
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Discussion of Surveying Techniques

• Short long distance journeys are
  underrepresented in DATELINE and other LD travel
  surveys
• Likely explanations
• Recall effects Respondents report what their
  remember
• DATELINE maybe misleading phrasing in the
  questionnaire ? Reise
• Selective underreporting of short journeys in
  DATELINE is probably country specific
• ? Impossible to transfer the results from
  Germany, GB, CH to other countries
• What makes respondents remember journeys?

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Discussion of Surveying Techniques
Journeys gt 100 km without overnight stay per
person per year
Journeys gt 100 km with overnight stay per person
per year
Journeys gt 400 km per person per year
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Discussion of Surveying Techniques

• LD surveys perform better for journeys
• gt 400 km
• With overnight stay
• GB NTS LD Questionnaire performs best with
  respect to short LD journeys, but shows fatigue

Reporting Week Number of reported long distance journeys
1 0.09
2 0.08
3 0.06
4 (mobility diary week) 0.11
Placement interview
Collection interview
mobility diary
3 week LD travel record
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Conclusions Availability of Long Distance Travel
Data Today

• Plausible DATELINE results for long long
  distance journeys

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Conclusions Availability of Long Distance Travel
Data Today

• Figures on long long distance journeys
  available from DATELINE
• Journeys gt 400 km
• Journeys with overnight stay (?)
• short long distance journeys do not seem to be
  adequately represented in DATELINE
• Figures on short long distance journeys often
  available from NTS surveys
• Within certain segments of travel the results of
  long distance travel surveys seem to be reliable,
  e.g. modal split

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Conclusions Availability of Long Distance Travel
Data Today

• Composite figures on long distance travel for
  Germany, GB, CH

Private Private Private Business Business Business
G GB CH G GB CH
Journeys per person per year Journeys per person per year Journeys per person per year Journeys per person per year Journeys per person per year Journeys per person per year Journeys per person per year
100-200 km 3.0 2.7 2.7 0.3 0.7 0.4
200-400 km 1.3 1.1 0.6 0.1 0.3 0.1
gt 400 km 0.8 0.8 0.8 0.1 0.1 0.1
Total 5.1 4.6 4.1 0.6 1.1 0.6
Average journey length km Average journey length km Average journey length km Average journey length km Average journey length km Average journey length km Average journey length km
323 310 370 346 277 291
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Conclusions Surveying techniques

• Mobility diary surveys better at capturing
  short LD journeys
• Especially 7 day diaries (identification of
  overnight journeys)
• Almost no recall/ fatigue effects
• Standardized formats ? comparable figures
• LD travel surveys necessary to capture journeys
  with overnight stays
• Mobility diary survey overnight
  journey survey complete picture of travel
• Ask people only what they remember maybe
  they remember less than we think