Ben-Elia, E. and Ettema, D. (2011) Changing commuters' behav- ior ...

esults sustain this association in three ways. First, there appear to be significant betweengroup
differences in the behavior change. Yeti users had relatively higher shares of driving
later compared to higher shares of driving earlier in the money group. Yeti users’ main
advantage was the real-time access to travel information whereas the participants in the
money group had to search for the same information i.e. it involved more effort. However, as
noted this result could also be confounded by prior arrangements with employers over
flexible working times which were more dominant with the Yeti group. Hence, we cannot be
certain if the different response is attributed to the Yeti treatment or related to
prearrangements which facilitated driving later. However, the information explanation is
strengthened by the fact that moderating this effect by group was not significant.
Second, access of travel information, mainly traffic but also public transport information,
intensified during the course of the experiment (pre/post-test comparison). Thus, decisionmaking
in a changed environment apparently increased the need for information about the
outcomes of alternatives. Third, information availability is positively associated with not
driving or driving later. Participants who frequently accessed public transport information and
who were actively perusing information over public transport connections were more likely to
avoid driving altogether. In addition, participants with higher frequency of accessing traffic
information where more likely to choose driving later. It seems therefore that information
acquisition and choice of avoidance behavior are clearly related. However causality here is
uncertain as participants could also increase information acquisition for the alternative they
found is best.
6. Summary and conclusions
The main conclusion regarding the use of rewards in encouraging commuters to change
behavior is that it actually works. Rewards are effective extrinsic motivators for travel
behavior change - here rush-hour avoidance. The monetary reward was likely perceived as
a gain with diminishing sensitivity, whereas the Yeti should be regarded as an in-kind reward
which had added endowment and instrumental qualities. The rewards were able to sustain
the behavioral change throughout the experiment. Nonetheless, it is still an open question
whether the change would be sustained in the long run and without rewards. We do not have
enough post-test observations to provide an answer apart from subjective assessments by
the participants. A second conclusion that can be drawn from this research is that the reward
influences the magnitude of change – an increase or decrease in rush-hour avoidance.
However the choice how to avoid – driving at other times, switching to another mode of
transport or working from home, is determined by external factors relating to participants’
personal and social characteristics, scheduling flexibility, history and information availability,
Although already of some interest to the travel behavior research community these issues
deserve further attention in future research.
As a closing remark, following the success of the current study, application of reward-based
schemes is now taking place across The Netherlands. Although some concern, based on
traffic simulation models, indicated that too many people might start changing their
schedules to gain a reward (Bliemer & van Amelsfort, 2008), the evidence in the field does
not support this claim. Their effectiveness in mitigating congestion, especially in situations
involving temporary road maintenance or lane closures has been verified (Bliemer et al.,
2009). A recent survey of firms also has shown positive attitude amongst employers towards
the reward scheme (Vonk Noordegraaf & Annema, 2009). So far, the majority of the Dutch
public (apart for the public transport users who are ineligible and consequently grumbling)
and the government are quite content with the results. However as recently published in the
media the (last) government also wanted to advance a punishment policy through universal
kilometer road charging – a decision that stresses the importance of well-informed,
evidence-based, as well as behaviorally-sound public policy.
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