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Technical Paper
Transportation P r o f e s s i o n a l
July/August 2009
Changing travel behaviour:
Lessons from ‘behavioural economics’
Road pricing and other fiscal means of influencing travel decisions have lost favour, but study of
travellers’ economic decisions suggests a new way of changing – or ‘nudging’ – behaviour. This
paper is by Dr Erel Avineri.
Introduction
Concerns over climate change, air
pollution, health and congestion on the
road network are leading governments
to take action to change the way people
travel. Individuals are being encouraged
to behave in more sustainable ways.
Economic interventions, such as road
user charging or fuel tax, have a
rationale but are unpopular. Insights
from behavioural economics, however,
inspire ‘softer’ interventions to
influence travel decisions without
limiting freedom of choice.
This article discusses how new
developments in behavioural economics
might be relevant to transport and
illustrates the use of ‘nudges’ to
encourage decisions in favour of
preferable travel options.
Locations for nudges: Intelligent use of information systems could trigger behavioural change
The standard economics approach to
changing travel behaviour
One of the main arguments in favour of
government interventions to reduce
demand for transport is the failure of
individual travellers to consider the full
consequences of their travel choices.
Effects on pollution and global
warming, as well as the congestion
imposed on other road users, are largely
ignored by the traveller decision making
processes. The key to the success and
effectiveness of an intervention would
be, according to neoclassical economic
theory, to “get the prices right”.
Governments, through economic
interventions, taxes and subsidies, try to
change travellers’ choices.
The promise of behavioural economics
In conventional transport studies, the
individual traveller is commonly seen as
a rational human being who tends to
maximize the benefits and reduce the
costs of travel. However, evidence from
behavioural, cognitive and social
sciences is painting a more complex
picture of decision making processes.
In real life the behaviour of travellers
is typified by limited cognitive resources
– for example, difficulties in processing
large amounts of data – bounded
rationality (in many cases we fail to
make the best choices) and emotional
and habitual behaviour.
Behavioural economics is a relatively
new branch of economics, which applies
insights from behavioural sciences to
better understand and predict how
people make economic decisions. One
of the key observations of behavioural
economics is ‘framing’ – how the
manner in which a choice is presented
to the individual affects his or her
decision. Studies provide evidence that
travellers fail to make the better travel
choices for themselves even in rather
simple tasks, and that they are strongly
influenced by the way travel
information is presented to them1.
One of the potential benefits of
behavioural economics is the
development of interventions that help
individuals by taking into account the
systematic mistakes and biases that
influence their choices. Thaler and
Sunstein2 suggest incorporation of small
features or ‘nudges’ in the environment
to attract peoples’ attention, highlight
the ‘right’ choices for them and alter
their behaviour. Similarily, the art and
science of ‘choice architecture’ could be
used to inspire design of information
provided to travellers, as part of a
measure such as a travel plan, or as a
principle in the design of travel
information systems. The following
example illustrates how a ‘nudge’ could
change travel behaviour.
Framing and “Loss Aversion”
People tend to feel and behave
differently when information is
presented (or ‘framed’) in terms of gains
or losses. The emotion of loss is more
powerful than that of gain. Roughly
July/August 2009
Technical Paper
Transportation P r o f e s s i o n a l
A
Commuting by car will take 20 minutes
Cycle-commuting will take 15 minutes
B
Commuting by car will take 20 minutes
Choosing to commute by bike, your journey will be 5 minutes shorter
C
Cycle-commuting will take 15 minutes
Choosing to commute by car, your journey will be 5 minutes longer
Figure 1 Framing Effects: Three ways of presenting travel information
speaking, losing £100 produces a
negative emotion twice as strong as the
positive feeling experienced when
gaining £100. Studies bring evidence
that travellers exhibit aversion to loss
and have a strong tendency to avoid
choices associated with losses.
The framing of choice outcomes as
gains or losses could be applied as a
nudge to encourage travellers towards a
specific choice. Figure 1 illustrates three
ways of presenting the same
information on the journey time of two
options: car and cycle commuting.
Under the conventional rational
choice model, the format of the
information should not matter. The
information presented by all three
formats is of the same content; it is the
difference in how it is presented that
could influence the choice – in a way
that cannot be explained or predicted
by classical economics.
It is difficult to predict how
‘unframed’ information on the options
(alternative A) will be interpreted and
used by the traveller. Framing cycling as
a choice that carries possible gain (as
illustrated in alternative B), or the even
stronger nudge (alternative C) where the
choice of commuting by car is framed as
a loss, are ways to make cycling appear
more attractive than the alternative.
None of the information formats impose
a restriction of the travel options for the
traveller. However, he or she is
encouraged to choose the option which
is considered to be preferable.
Salience
Behavioural change is more likely if
feedback on behaviour is given to
travellers or the impacts of their
journeys made more conspicuous. Many
drivers have already experienced
nudges; some Advanced Vehicle Control
& Safety Systems sound high pitch alerts
when drivers exceed a speed limit or
when leaving a lane. This warning
signal serves as a nudge – providing
feedback on behaviour and helping the
driver avoid behaviour that leads to the
sound alert.
A specific challenge faced by
designers of transport systems is how to
inform travellers about the
environmental costs of their journeys.
Carbon emissions are invisible, so it is
therefore difficult to associate travel
behaviour with environmental costs.
New research at the University of the
West of England explores how to
effectively incorporate nudges in the
design of travel information systems.
Conclusions
Nudges can help overcome cognitive
bias, highlight better choices and
increase the effect of behavioural
change – without restricting choices. In
liberal democratic regimes, where
public and political acceptability of
economic interventions are low, the
nudging of travellers through ‘choice
architecture’ could be one of the more
promising approaches to deal with the
urgent need for radical behavioural
change.
The effectiveness and acceptability of
interventions to change travel
behaviour may be enhanced if more
consideration and emphasis is given to
the design of travel information through
nudges; however this should be seen as
complementary rather than an
alternative to other measures.
A specific area of application in which
choice architecture might be relevant
and effective in changing travel
behaviour is the design of Advanced
Traveller Information Systems. Careful
design of the way information is
provided to the user could help to
influence travel choice. With the
technological level of modern systems
and the widespread availability of travel
information services, the incorporation
of nudges into such systems is easier
and more cost effective than ever.
This could be the trigger to
achieve the behavioural change we
urgently need.
Dr Erel Avineri is a reader in travel
behaviour at the University of the West
of England’s Centre for Transport &
Society (CTS) in Bristol. Erel has managed
projects and acted as a consultant to
more than 50 leading companies and
government agencies for transport and
logistics. He is a member of the US
Transportation Research Board's
Committee on Artificial Intelligence, and
an Honorary Secretary of the
Universities’ Transport Study Group.
For CTS, Erel is leading research on
travel behaviour, what influences it, how
to predict it, and how to design demand
management measures to change travel
behaviour. His current teaching
responsibilities include lecturing in
various transport planning modules and
leading postgraduate modules on
Changing Travel Behaviour and Transport
Economics & Appraisal.
Xtra-info:
www.transport.uwe.ac.uk/staff/erel.asp
This paper has been produced and peer
reviewed on behalf of the IHT Transport
Policy Board.
Additional reading:
• Creatures of Habit (The Art of
Behavioural Change) by J Prendergrast,
B Foley, V Menne and AK Isaac
www.smf.co.uk
• Positive Energy (Harnessing People Power
to Promote Climate Change) by S Retallack,
T Lawrence with M Lockwood
www.ippr.org
References
1. Avineri, E. and Prashker, J.N. (2006), The
Impact of Travel Time Information on
Travelers' Learning under Uncertainty.
2. Thaler, R. and Sunstein, C.R. (2008).
Nudge: Improving Decisions about
Health, Wealth and Happiness.
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