WG3 Torino 051007 Kuhnimhof Long distance travel i

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

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

Introduction: 

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

Relevant Sources for Long Distance Travel Data : 

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

Relevant Sources for Long Distance Travel Data : 

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”

Relevant Sources for Long Distance Travel Data : 

Relevant Sources for Long Distance Travel Data

Problems of data comparability : 

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

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques The Surveys under Scrutiny

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques Definition of long distance travel used Journeys > 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

Discussion of Surveying Techniques : 

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

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques Results: Number of LD-Journeys per person per year by journey length

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques Results: Number of LD-Journeys per person per year by journey length Retrospective CATI, 2 weeks Retrospective CATI, 4 months

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques Results: Number of LD-Journeys per person per year by journey length Placement interview 3 week LD travel record mobility diary Collection interview

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques Journeys 100 – 400 km per person per year Journeys > 400 km per person per year

Discussion of Surveying Techniques : 

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?

Discussion of Surveying Techniques : 

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

Discussion of Surveying Techniques : 

Discussion of Surveying Techniques LD surveys perform better for journeys > 400 km With overnight stay GB NTS LD Questionnaire performs best with respect to short LD journeys, but shows fatigue Placement interview 3 week LD travel record mobility diary Collection interview

Conclusions: Availability of Long Distance Travel Data Today : 

Conclusions: Availability of Long Distance Travel Data Today Plausible DATELINE results for „long“ long distance journeys

Conclusions: Availability of Long Distance Travel Data Today: 

Conclusions: Availability of Long Distance Travel Data Today Figures on “long” long distance journeys available from DATELINE Journeys > 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

Conclusions: Availability of Long Distance Travel Data Today: 

Conclusions: Availability of Long Distance Travel Data Today Composite figures on long distance travel for Germany, GB, CH:

Conclusions: Surveying techniques: 

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