Presentation given to University Transport Study Group on 6th January 2011. For more information, you can contact me via about.me/simpsdj

1. Route Choice Variability:
A reactive or proactive decision?
David J Simpson
PhD Research Student

2. Variability Happens

3. • Habitual travel behaviour is characterised not
solely by repetition but also by variability (Hanson
& Huff 1990)
Variability Happens

4. • Habitual travel behaviour is characterised not
solely by repetition but also by variability (Hanson
& Huff 1990)
• Some definitions of habit
– “recurring manner of response to a given
situation” (Reading 1977)
– “regularly repeated action on the part of an indivudal that
is learnt and is observable to others” (Newcomb 1964)
– Involves “accommodation, adaptation and
adjustment” (Popplestone & McPherson 1988)
Variability Happens

5. Travel Variation

6. • Habitual travel have many variable characteristics
– mode
– journey-chain
– reference to chosen path (route)
Travel Variation

7. • Habitual travel have many variable characteristics
– mode
– journey-chain
– reference to chosen path (route)
• Historically less work has been undertaken
surrounding spatial variations of habitual travel
– Recent renewed interest now the data is available
although it is largely road based.
Travel Variation

8. Categorising Travel Variation

9. • Huff & Hanson (1986) have shown that variation
exists
Categorising Travel Variation

10. • Huff & Hanson (1986) have shown that variation
exists
• Hanson & Huff (1990) later proposed to
differentiate among three very different sources of
variation, later expanded by Kitamura et al (2006)
– Systematic
– Ephemeral
– Structural
Categorising Travel Variation

11. Travel Survey Methodology

12. • Travel surveys have a long history in academic
research
– Travel diaries are dominant despite some issues
• Non response
• Drop-off
• Trip ommission
• Human error
Travel Survey Methodology

13. • Travel surveys have a long history in academic
research
– Travel diaries are dominant despite many problems
• Non response
• Drop-off
• Trip ommission
• Human error
• GPS Methodology offers new opportunities
– Methodology becoming increasingly important despite
it’s own problems
• Cold Starts
• Urban Canyon
Travel Survey Methodology

14. Ipsos MORI

15. • Ipsos MORI are the second largest media research
firm in the UK
– Working on a project measuring twenty thousand
participants for ten days over three years.
– Offered this data to UCL
Ipsos MORI

19. Is a ten day methodology period enough?

20. • No literature to indicate the frequency variations
are undertaken
Is a ten day methodology period enough?

21. • No literature to indicate the frequency variations
are undertaken
• Typical placement of Ipsos MORI’s devices capture
six weekdays and four weekend days
– Unknown whether this is sufficient to analyse travel
variability
Is a ten day methodology period enough?

22. • No literature to indicate the frequency variations
are undertaken
• Typical placement of Ipsos MORI’s devices capture
six weekdays and four weekend days
– Unknown whether this is sufficient to analyse travel
variability
• Focus Group methodology used to gain qualitative
information as to the nature of individual travel
behaviour
– including frequencies of travel repetition and variability
Is a ten day methodology period enough?

23. • Nineteen participants over four focus groups
• Three locations
– London (2)
– Manchester
– Liverpool
• Snowballing recruitment method used
Focus Groups

24. • Nineteen participants over four focus groups
• Three locations
– London (2)
– Manchester
– Liverpool
• Snowballing recruitment method used
• All types of variation were alluded to in the focus
groups
Focus Groups

25. • Work was the most common type
• Exercise the second most common type
– All trips were spatially/temporally similar
Results: Systematic Variation

26. “It varies in the week but its three times a week.”
Participant M (male, non-driver, 18-24, Manchester)
Results: Systematic Variation

27. “Yep, play football down in Oval. So usually travel by
the tube from, er, from Farringdon” “roughly the same
time give or take an hour, every Monday and
Wednesday.” Participant K (male, non-driver, 18-24,
London).
Results: Systematic Variation

28. • Events included
– Moving house
– Change in work location/status
– Changes in routes available
Results Structural Variation

29. • Weather
• Delays on Public Transport (non drivers)
• Traffic (drivers)
• Reducing the physical effort (laziness)
Results Ephemeral Variation

30. “I actually take different routes - to mix it up a bit. … I
normally go Canada Water to Green Park then
Victoria Line up to Euston or Warren Street, or I go
Canada Water to London Bridge and take the
Northern Line to Euston, and sometimes if I am
feeling really lazy I take the Jubilee Line from
Canada Water to Baker Street and take the
Hammersmith or Metropolitan Line to Euston Square
just because it is a bit closer to my office - which isn’t
a very good reason because it actually takes me
longer. But it is interesting to mix it up.” Participant B
(male, driver, 18-24, London).
Results: Ephemeral Variation

31. • Hanson & Huff (1990)
– Systematic
– Ephemeral
– Structural
Categorising Travel Variation

32. Categorising Travel Variation

33. • Participants were often not specific in their
systematic and ephemeral variations
– “a couple of times per year”
– “a couple of times per month”
– “a couple of times per week”
• All common phrases used in the focus groups
• Exercise is an especially good example
• “Sporadic” mentioned by three participants
Frequency of Variations

34. • All focus group participants gave evidence of
habitual travel variability
– evidence route variability is taking place
• Complex nature of variations required an
expansion of Hanson & Huff’s (1990) work for
successful and meaningful categorisation
• Estimates of frequency from the participants are
often the best available.
• Ipsos MORI’s ten day methodology is too short to
fully comprehend habitual travel variability
Conclusions

35. • Hanson, S. & Huff, J. (1990) Measurement of habitual behaviour: Examining
systematic variability in reptitive travel IN Jones, P. (ed) Developments in
Dynamic and Activity-Based Approaches to Travel Analysis; Gower: Aldershot,
UK. (pgs 229-249).
• Huff, J. & Hanson, S. (1986) Repetition and variability in urban travel,
Geographical Analysis 18, 97-114.
• Kitamura, R., Yamamoto, T., Susilo, Y.O. & Axhausen, K.W. (2006) How routine
is a routine? An analysis of the day-to-day variability in prism vertex location,
Transportation Research A 40, 259-279.
• Newcomb, T.M. (1964) Habit IN Gould, J. & Kolb, W. (eds) A Dictionary of the
Social Sciences, Tavistock: Norwich, UK.
• Popplestone, J.A. & McPherson, M.W. (1988) Dictionary of Concepts in
General Psychology, Greenwood Press: Westport CT, USA.
• Reading, H.F. (1977) A Dictionary of the Social Sciences, Routledge & Kegan
Paul: Guildford, UK.
References

36. Slides and contact details are found at
http://about.me/simpsdj
d.simpson@ucl.ac.uk
Thank you for your time
Thank You

37. Slides and contact details are found at
http://about.me/simpsdj
d.simpson@ucl.ac.uk
Thank you for your time
Any questions?
Thank You