Those familiar with psychology, will be aware of Pavlov’s dogs and his reinforcement theory of motivation1; here the application of incentives provides positive reinforcement for a given behaviour, increasing the likelihood of those behaviours being performed in future. The theory suggests that behaviour is driven by consequences; people are extrinsically motivated to behave in a certain way when they receive positive reinforcement for that behaviour. For example, if one is rewarded for choosing to use public transport rather than drive, this may encourage the person to repeat the behaviour in the future. The COM-B model of behaviour2 outlines three mechanisms by which a behaviour change intervention might be effective. The theory is based on the dynamic relationship between one’s capability, opportunity, and motivation. Capability refers to one’s attributes (both physical and mental), opportunity relates to environmental factors such as sufficient resources, and motivation refers to the cognitive processes that influence and direct our behaviour. This theory relates to the application of incentives through motivating people to try greener modes of travel as the more they engage with the behaviour, the more capable they become which creates greater likelihood of sustainable behaviour change. Lastly, the theory of planned behaviour3, dating back to the early 1990’s, predicts the intention of a behaviour based on attitudes towards the act, subjective norms, and perceived behavioural control. In the context of green travel behaviours, this theory might argue, for example, that road users can be influenced to cycle to work instead of drive if they believe that ‘cycling to work will improve my health’ (attitudes), ‘my partner would appreciate and respect me if I look after my health’ (subjective norms), and ‘the office is only a 20-minute cycle away, I am capable of doing this’ (perceived behavioural control). Incentives fit into this theory as if one is rewarded for completing a particular behaviour, in this instance choosing cycling to work over driving, their attitudes, norms and perceived behavioural control become stronger and the behaviour is more likely to continue.
Outside of theory, there are a number of success stories demonstrating the effectiveness of incentives in practice. For example, in the healthcare sector, evidence from a review of 33 trials4 covering over 21,600 people showed that people receiving financial rewards (100-700 USD) were more likely to have stopped smoking than those in the control group, with success rates continuing after incentives cease. No significant difference was found between trials paying smaller amounts compared to those paying larger amounts.
For those of us working in the transport sector, decarbonisation of our transport system is a critical challenge; in short, seismic changes in our transport behaviour are urgently needed in order to reduce the contribution of transport emissions to climate change. Some examples of successful incentive schemes to reduce car dependence can be found across Europe:
1. Spitsmijden5
A series of four experiments was conducted in The Netherlands between 2006 and 2009 to understand ‘peak avoidance’. The experiments rewarded commuters with positive incentives (EUR 3-7 per day, or credits to purchase a smartphone) if they avoided travelling by car during peak times (7:30-9:30am). Participants’ driving behaviours were tracked using telematics systems in their cars, and travel diaries were completed two weeks prior to, during and one week after the experiment. The results showed that of the participants who received a EUR 3 reward, 35% travelled outside of the peak time, 9% shifted from car to public transport, 1% cycled, 1% worked from home and 54% did not change their behaviour. With a higher financial incentive of EUR 7, 44% of participants travelled outside of peak time, 13% switched to public transport, 1% cycled, 3% worked from home and 39% did not change their behaviour.
Take home message: Larger financial incentives can reduce car use.
2. Bella Mossa6
This was a 6-month scheme implemented in 2017 in Bologna, Italy. Here residents were incentivised to reduce their reliance on cars through rewarding the use of alternative transport modes, such as walking, cycling, or using public transport. Incentives took the form of ‘points’ which could be redeemed for goods and services in local shops and retailers. Following the 6-month pilot, 15,000 people had taken part and made 895,000 sustainable transport journeys totalling 3.7 million kilometres. It was estimated that those journeys saved 750 tonnes of CO2 emissions. Self-report survey data collected during the pilot suggested a decrease in solo car use, with 80% of ‘green’ journeys reportedly replacing a car trip.
Take home message: Incentive schemes can create a sense of community and support the local economy.
3. SMART7
This was a scheme carried out in Sweden with the aim to incentivise users of conventionally fuelled vehicles to change their behaviour through award of positive incentives for making sustainable transport choices. This scheme released weekly individual challenges based on 1,050 participants’ past travel behaviours. A point system was implemented whereby participants could earn 10 points per km of cycling or walking and 3 points per km of travel on public transport. Points were converted to benefit a chosen charity, to explore altruism as a motivation type. Results showed that positive incentives had an impact on travel behaviour; users who ‘accepted’ a weekly challenge drove an average of 29 fewer km for that week. However, it was also found that the impact was limited to the week that users accepted a challenge; indicating a rebound after the challenge had been completed. Additional research is needed to establish long-term effects of incentive-based behaviour change.
Take home messages:
- Weekly challenges with a sense of competitiveness can help reduce car use.
- Rebound effects are important – long-term impacts of schemes need to be researched.
At TRL, we understand that incentivising behaviour is a critical part of the armoury for achieving the goal of net-zero greenhouse gas emissions by 2040. Incentives are distinct from disincentives; some success has been realised with schemes, such as the Ultra-Low Emission Zone and Congestion Charge in London, which disincentivise higher-carbon choices, however, there have been few schemes to date in the UK which have applied incentives to the same scale. We must harness the opportunity to learn lessons from successful interventions in other industries, such as healthcare, and from other countries, such as those outlined above.
At the core, we need effective ways of rewarding those who choose green(er) modes of transport over polluting modes – in particular, fossil-fuelled single-occupancy cars which are collectively the worst offenders. We have an opportunity to target high car use through carefully designed incentives and create a sustainable shift towards greener travel behaviours. To ensure incentive schemes are as effective as possible we recommend the following areas are considered:
1. Customise the approach: The design of incentive schemes needs to be tailored to the target audience - some people are more likely to be influenced by this sort of intervention than others. Consider using segmentation techniques to develop customised approaches - this should also include analysis of what types of positive incentives are likely to be most effective for the target audience.
2. Plan for recruitment and ensure high uptake: High uptake is needed in order to have a significant impact on emissions, congestion and modal share. Consideration is needed regarding how to reach a large number of potential users. For example, partnerships with large employers could be a good way of reaching commuters, thereby influencing the way that large numbers of people travel to work.
3. Monitoring and evaluation (M&E) is critical: Design the scheme with a plan for M&E embedded at the start. Without this it will not be possible to reliably measure the impact of the scheme, and there will be a lack of evidence on how to make it more effective in future.
4. Consider partnering up: Incentive schemes can benefit from partnerships between employers, local retailers, application developers to allow for piloting and testing, personalisation of rewards and gamification elements through Smartphone applications.
References
- Pavlov, I (1928). Lectures on conditioned reflexes. New York: International Publishers
- Michie, S., van Stralen, M. & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Sciencel. 6 (1). doi: 10.1186/1748-5908-6-42
- Azjen, I. (1991). The theory of planned behaviour. Organisational behaviour and human decision processes. 50 (2): 179-211. https://doi.org/10.1016%2F0749-5978%2891%2990020-T
- Notley, C., Gentry, S., Livingstone-Banks, J., Bauld, L., Perera, R. & Hartmann-Boyce, J. (2019) Incentives for smoking cessation. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD004307.pub6
- Bliemer, M., Dicke-Ogenia, M. & Etterna, D. (2010). Rewarding for avoiding the peak period: A synthesis of four studies in the Netherlands. Civil engineering and geosciences. https://repository.tudelft.nl/islandora/object/uuid:f3cfcfd7-4e17-4400-954b-06347ce006f3/datastream/OBJ/download
- Bella Mossa Retrieved from: https://www.betterpoints.ltd/blog/20000-people-incentivised-to-travel-more-sustainably-in-bologna/
- Hjalmarsson-Jordanuis, A., Amelsfort, D. & Dolins, S. (2017). Rewarding sustainable transportation choices – impacts of app-based outreach and incentive distribution. Retrieved from https://www.diva-portal.org/smash/get/diva2:1282201/FULLTEXT01.pdf
