Travel mode choice: Relative value of
transport alternatives
Brno, April 6, 2017
Inge Brechan
Behavioral choice
•
To use tobacco or not?
– How often or how much: Never, some time, all the time?
– Cigarettes, shag, or snus? Brand A, brand B, brand C?
•
To travel or not?
– How often or how much: 10 journeys, 10 km, or 10 minutes?
– Bike, bus, or car?
•
Choosing between alternative actions depends on the
relative preference among the alternatives rather than
the absolute value of each alternative (Ajzen & Fishbein, 1969)
Theory of planned behavior
(Ajzen, 1991)
Attitude toward the
behavior
Subjective norm
Perceived
behavioral control
Behavioral
intention
Behavior
Former research
Brechan, I. (2016). Travel intention: Relative value of alternatives. Human
Affairs: Postdisciplinary Humanities & Social Sciences Quarterly, 26,
390–399.
Former research
Brechan (2016)
Past behavior
Attitude toward
the behavior
Prescriptive
behavioral norm
Controllability
Self-efficacy
Behavioral
intention
Absolute measures
Former research:
Public transport
Past behavior
.28***
Attitude toward
the behavior
.28***
Prescriptive
behavioral norm
Controllability
Self-efficacy
.33***
Brechan (2016)
Behavioral
intention
Relative measures
.41***
Past behavior
.22***
Attitude toward
the behavior
.23***
-.04ns
-.03ns
.16***
.20***
Prescriptive
behavioral norm
Controllability
Self-efficacy
New study: Conceptual model
Attitude toward the
behavior
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
Behavioral
intention
Behavior
Longitudinal study
• Survey of 229 employees
• Organizations close to Oslo city center (university, research
institutions, hospital)
• Questionnaire measuring the relevant factors, using several
items, with respect to travel mode to/from work the following
week. a > .70
• Travel diary completed during the following week
Measures
• All measures were repeated for three modes of transport: Car,
public transport, and bicycle.
• Behavior: Used the travel mode to/from work the following week,
yes/no
– Number of journeys, max 10
• Behavioral intention, two items, e.g., «How likely are you to travel
by car next week?» from 1 (very unlikely) to 7 (very likely)
• Attitude toward the behavior, seven items, e.g., «Would travelling
by car be a good solution to your transport needs next week?»
from 1 (very bad) to 7 (very good)
Measures
•
•
•
•
Prescriptive behavioral norm, three items, e.g., «How do you think your
friends think you should travel next week?» from 1 (definitely not by car) to
7 (definitely by car)
Descriptive behavioral norm, three items, e.g., «How do you think your
friends would travel next week?» from 1 (definitely not by car) to 7 (definitely
by car)
Self-efficacy, three items, e.g., «If you decided to, how confident are you
that you could travel by car next week?» from 1 (very unconfident) to 7 (very
confident)
Controllability, three items, e.g., «How likely is it that a car would be an
available alternative for your transport needs next week?» from 1 (not
available, for sure) to 7 (available, for sure)
Relative measures
Relative measures was computed by dividing the absolute measure
on the mean of the absolute measures of all three transport modes,
e.g.,
𝑅𝑒𝑙. 𝐴𝑡𝑡. 𝑐𝑎𝑟 = 𝐴𝑡𝑡. 𝑐𝑎𝑟.
𝐴𝑡𝑡.𝑐𝑎𝑟.+𝐴𝑡𝑡.𝑝𝑢𝑏.+𝐴𝑡𝑡.𝑏𝑖𝑐.
3
Explaining intention and behavior
Explaining intention:
Absolute measures
Public transport
Relative measures
Attitude toward the
.45***
behavior
Attitude toward the
behavior
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
.42***
.17**
.01ns
.11*
Behavioral
intention
.05ns
.27***
.21**
-.03ns
.21***
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
Explaining intention:
Absolute measures
Car
Relative measures
Attitude toward the
.32***
behavior
Attitude toward the
behavior
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
.35***
.20***
.01ns
.09ns
Behavioral
intention
.02ns
.10ns
.27***
.38***
.22***
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
Explaining intention:
Absolute measures
Bicycle
Relative measures
Attitude toward the
.41***
behavior
Attitude toward the
behavior
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
.50***
-.03ns
.01ns
-.05ns
Behavioral
intention
.03ns
.38***
.32***
.01ns
.02ns
Prescriptive
behavioral norm
Descriptive
behavioral norm
Self-efficacy
Controllability
Explaining behavior
Effect (Odds Ratio) of
behavioral intention
(absolute measures)
• Car: 2.40***
• Public Transport:
2.34***
• Bicycle: 2.25***
p < .001
p < .01
Discussion
•
•
Not finding a significant predictive contribution of relative preference for
travelling by public transport, controlling for absolute intention, may be
explained by the strong negative kurtosis in the distribution of intention to
travel by public transport in this study. Participants’ intention to travel by
public transport was mostly either very low or very high.
This may be related to the fact that the sample of participants in this study
was recruited from workplaces in the center of a large city. If you live in the
city and work in the city, public transport services will most likely be highly
available. If you live outside the city and work in the city, public transport
services will most likely be less available.
Discussion
•
•
•
•
Results support the Theory of Planned Behavior
Results support the idea of relative preference among alternatives in
choice situations.
Prior research may have underestimated the predictive power of the
Theory of Planned Behavior when failing to consider relative preferences
in choice situations
Politicians, officials, idealists, or anyone interested in influencing people’s
travel mode choice must consider not only the value or utility of the
targeted travel mode, but also the value of alternative travel modes