Behaviour Change - Science and Technology Committee Contents


26 January 2011

Members of the Sub-Committee present were Baroness Hilton of Eggardon, Lord Krebs, Lord May of Oxford, Baroness Neuberger (Chairman), Baroness O'Neill of Bengarve, Baroness Perry of Southwark and the Earl of Selborne. In attendance were Daisy Ricketts (Clerk) and Rachel Newton (Policy analyst).

The speakers were: Dr Jillian Anable, University of Aberdeen, Centre for Transport Research); Dr Sally Cairns (University College London and Senior Research Fellow of the Transport Research Laboratory); John Dowie (Director of the Regional and Local Transport Directorate, Department for Transport); Dr David Ogilvie (Medical Research Council Epidemiology Unit and UKCRC Centre for Diet and Activity Research, Cambridge); Dr Steve Skippon (Principle Scientist, Shell Global Solutions).

Other participants were: Professor Philip Goodwin (University of the West of England); Ms Carey Newson (Behaviour Change Specialist, Transport for Quality of Life).

An overview of current policies to change travel behaviours to reduce car use (Mr John Dowie)

Mr Dowie noted that available measures for changing travel behaviour included creating modal choices through improvements to public transport services and infrastructure, fiscal and regulatory measures, information provision and marketing. Historically, transport policy had been focused on infrastructure but there had been an increasing recognition that alternative persuasive techniques to change behaviour were also required. He noted that changes to infrastructure were not as effective in isolation as when combined with these sorts of techniques.

Past initiatives with the Department for Transport (DfT) had included small scale demonstration projects but the future policy direction was towards large scale, integrated policy packages. The Sustainable Travel Towns programme was introduced to test the potential of an integrated approach. It ran between 2004 and 2009 and was funded by £10 million of DfT funding together with £5 million of local funding. The towns of Darlington, Peterborough and Worcester were chosen after a competition; the three towns had varying socioeconomic contexts. The towns employed a range of measures, including personal travel planning, public transport information and marketing, travel awareness campaigns, cycling and walking promotions and car clubs. The results across all three towns showed a 9% reduction in car trips; a 10 to 22% increase in bus trips; a 26 to 30% increase in cycle trips; and a 10 to 13% increase in walking trips. The Cycle Demonstration Towns programme was conducted on the same basis; results demonstrated a 27% increase in cycling levels across the participating towns.

The Local Transport White Paper, Creating Growth, Cutting Carbon, published in January 2011,[346] placed localism at the heart of the transport agenda. The Paper recognised the need for behavioural change and used the Nuffield Ladder of Interventions to argue that the starting point should not be to restrict choice but to enable and encourage more healthy and sustainable choices. The Local Sustainable Travel Fund would provide £560 million to local authorities over four years to build on the previous successful Sustainable Travel Towns and Cycling Towns programmes.

The DfT was also developing policies on alternatives to travel to help reduce car use. These included promoting information and communications technology to reduce the need for travel and working across the public sector to promote alternatives to travel. Eco driving was also an area of policy interest.

Embedding learning from behavioural science within Government was an important concern. An in-house toolkit had been developed for policy makers in the DfT and knowledge about behaviour change was being shared with local authorities.


The results from the Sustainable Travel Towns were discussed further. The percentage increase in cycling was from a low base. The evaluation was completed at a time when the programmes were still running and it was not yet clear whether the improvements would persist. For an investment of only £10 million however it was considered by some to be a successful programme and to have provided good value for money.

The meaning of the word "nudge", in the context of "nudging not nannying", was discussed. It was suggested that "nudge" ought to be interpreted narrowly to include only soft or light touch measures. It was suggested that ministers faced a dilemma because there was a broadly held view that harder measures were necessary in transport to lock in traffic reduction. Nudges would not be sufficient alone but needed to form part of a package of interventions. It was argued that the Sustainable Travel Towns demonstration showed that light touch interventions targeted to individuals were complementary to infrastructure changes.

The discrepancies between the levels of car use in the United Kingdom and in Continental Europe were discussed. Different levels of investment in interventions were identified as a key reason for this.

The role of behaviour change in delivering emissions reductions (Dr Steve Skippon)

Dr Skippon argued that the effects of carbon emissions were cumulative and that even modest delays in reducing emissions would result in a much higher likelihood of a global temperature rise. The projected trend across Europe was continued growth in light duty (cars, vans and motorbikes) kilometres travelled. Shell's transport emissions modelling suggested that, for the EU light duty sector, the best achievable reduction in carbon emissions as a result of technology alone could mean that by 2050 annual emissions would be reduced by 80%. However such reductions would not happen quickly enough to limit the accumulation of carbon in the atmosphere and so global temperature rises. Changes to travel behaviour would therefore be necessary in addition to technology change because they could be implemented early and so have an impact on cumulative emissions.

A number of ways in which to change behaviour to reduce emissions from car use were identified, including a reduction in journeys undertaken, travel mode choice, downsizing of vehicles, and adoption of fuel-efficient driving styles. Modelling showed that the changes in behaviour that could be achieved through voluntary measures, such as public awareness and information campaigns and travel planning, would have some impact on cumulative emissions, but not enough. Changes could also be brought about by strong measures, including measures to encourage modal shift like parking restrictions, and higher taxes on larger vehicles. Modelling suggested that these strong measures would be more effective in limiting cumulative emissions than the voluntary measures. Behaviour change would not be sufficient in isolation however. The full range of technological options would also be required if transport's contribution to global targets was to be approached.

Dr Skippon provided examples of the potential impact of behaviour change interventions in the road transport sector in the United States. He stressed that it was hard to translate conclusions from interventions in the United States, as the opportunities for behaviour change were very different there. For example, many more people drove large cars and so vehicle downsizing could have more of an impact than in Europe.

An introduction to the factors that influence travel behaviours and the possible mechanisms and interventions to affect those behaviours (Dr Jillian Anable)

Dr Anable noted that the separation of behaviour and technology was not a useful polarisation. Travel behaviour was not just about mode choice but encompassed the sort of cars that were purchased, how they were driven and how much they were used. Carbon pathways analysis conducted by the DfT showed that distance of trips was an important consideration. Short trips (under 5 miles) accounted for 20% of carbon emission. The Sustainable Travel Towns project demonstrated that the largest proportion of total reduction in car use (in terms of distance driven) came from small changes to the longest trips, although the most significant changes in behaviour as a result of the programme was seen in short trips.

Recent studies suggested that car use had peaked and that the downward trend in the uptake of sustainable travel modes was starting to reverse. There was also a drop in the number of people who held a driving licence. The reasons for these patterns were not known, although it was noted that a recent survey by the RAC identified changing attitudes toward travel.

Behaviour change was identified as a two way process, which was more flexible and volatile than was usually understood: some people gave up driving and started to use public transport, and others stopped using transport and started to drive on a continuous basis. Each decision-making process needed to be targeted differently to achieve net movement in a sustainable direction.

There had been examples of successful behaviour change, including the Sustainable Travel Towns project, the London congestion charge, pedestrianisation and public transport investment. Behaviour change was shown to result from a combination of many different determinants, encompassing factors subjective and objective to the individual, and subjective and objective to the collective.

Interventions had traditionally been classified either as structural, or collective and motivational. Examples of structural interventions included fiscal measures, provisions of alternative modes of transport, regulatory interventions and land use planning. Examples of collective and motivational interventions included information provision and social marketing. All of these interventions should be considered to be behavioural.

Dr Anable explained the language of "smarter choices" which was used often in relation to travel interventions. It was commonly understood to include psychological techniques to influence behaviour through engaging with individuals, rather than infrastructure. Some of the policy lessons that had been learnt through the use of smarter choices, including in the Sustainable Travel Towns programme, were: behaviour change was greater where service improvements were combined with marketing and promotion; marketing and information was rarely sufficient on its own; medium length and commuter trips offered the best opportunity in terms of car mileage savings; local context and partnerships were important; behaviour change needed to be locked-in to prevent rebound; and individual behaviour changes would be diluted by a lack of regional and national policy consistency.

The strengths of the evidence-base were identified as case studies, behavioural and psychological studies and econometric studies. The weaknesses were longitudinal studies, controlled design, action research, and understanding social practices and interpersonal influences.

Optimism about technology and pessimism about behaviour amongst policy makers was not based on good evidence. Policymakers were not using the evidence when they focused on the individual and the rational and when they emphasised the evaluation of the impacts of separate policy instruments.


The availability of systematic reviews of the evidence about how to reduce car use was discussed. It was suggested that there was a large volume of material but few high quality methodological studies, such as randomised controlled trials. The necessity of randomised controlled trials was discussed. Some suggested that, while it is not always possible to use them, wherever possible controlled trials or other high quality methodologies should be employed. It was noted that it was not always appropriate to attempt to evaluate the different components of packages of interventions separately, since a range of measures was often necessary in order for any change in behaviour to be achieved.

The financial cost of car use was discussed. Perceived cost was considered to be more important than actual cost, and initiatives to shift the cost of car use so that it was less fixed and more directly correlated to distance travelled were discussed. It was noted that such initiatives would be difficult to introduce and that the losses to certain groups would be large.

The potential proportion of achievable change was discussed. Some suggested that change could only be sought on the margins, in around 5% of the population. Others disagreed, arguing that there was potential to change the behaviour of 30% of the population over a period of two to five years.

The impact of age on travel behaviour was discussed. It was noted that there was a real decline in car use amongst the elderly and young adults. Amongst the elderly, responses to stopping using cars varied widely depending on their expectations and capabilities. Young urban professionals were identified as a group who tended not to use cars, and this was considered to be a new trend. There was a high proportion of cycling among this group, particularly in London. Bicycle brands were becoming more expensive, which suggested that some people saw a bike as a status symbol in the same way that many people saw cars. It was not clear however how the behaviour of young urban professionals would change as they grew older.

An overview of the challenges of conducting effective evaluations for interventions designed to change travel behaviours (Dr Sally Cairns)

Dr Cairns outlined the key questions for an evaluation to consider: what has happened to travel behaviour; why have the changes occurred and to what extent can they be attributed to the interventions; and, what are the wider implications of those changes. The example of the Sustainable Travel Towns programme was used to illustrate this.

Evaluating what happened in the Sustainable Travel Towns was achieved by comparing data from the towns with national trends. Town data included household travel surveys, surveys in schools and workplaces, and counts of vehicles, cyclists, pedestrians and bus passengers. National data used included the National Travel Survey (specific data for medium sized urban areas) and the National Road Estimates (urban roads data). The value of triangulation of data sources was emphasized.

The evaluation of why changes occurred in the Sustainable Travel Towns was informed by in-depth interviews with those delivering initiatives, local authority officials, bus companies, those responsible for data collection and other relevant organisations. Contextual data was also gathered on the towns, such as population changes and levels of employment in order to understand what else might have caused change. Some of this information in relation to bus use in Worcester was demonstrated in graphical form; the graph showed the changes in bus patronage relative to the implementation of different initiatives. It was noted that change had been achieved through a combination of improvements in services, discounted fares and promotional campaigns, and it was not possible to assess the effect that any one of those measures would have had in isolation. It was noted that no long term follow-up was being conducted in the Sustainable Travel Towns following the initial evaluation, but that this could be insightful.

The key lessons identified for future evaluation were that good practice usually included controls or benchmarking; triangulation of data sources; and understanding not only what had happened but the context in which it had happened. Full evaluation could give invaluable results but was likely to be complex, time consuming, expensive and not a precise science.

Travel behaviour interventions from a public health perspective (Dr David Ogilvie)

Dr Ogilvie provided an overview of the evidence for travel behaviour interventions from a public health perspective. It was often unrealistic to expect to be able to test the whole causal chain, from intervention to ultimate health improvement, within a single study. The benefits of physical activity for health were clearly established; the greater current challenge was evaluating the impact of interventions to change travel behaviour on overall levels of physical activity.

Outcome measures for travel behaviour and physical activity were not synonymous. Questionnaires were widely used for estimating physical activity and energy expenditure from the time or distance travelled, but the precision of these estimates could be improved by measuring behaviour more objectively using devices such as accelerometers, heart-rate monitors and Global Positioning System receivers.

It was suggested that randomised controlled trials could be applied to some interventions but not all. They were underused in travel interventions; personalised travel planning provided a good opportunity for controlled trials but they had not been used. Sometimes a 'natural experiment' approach was more appropriate, particularly for interventions such as charging schemes and infrastructure changes. The Medical Research Council was developing guidance on the evaluation of natural experimental studies.

The 2009 report from the House of Commons Health Committee on health inequalities was cited as providing a list of desirable qualities of a robust evaluation.[347] Among the most important of these was adjustment for the counterfactual; even if there were no external control group, other methods were available for estimating what might have happened without the intervention. Social distribution of effects was also identified as an important measure. Behaviours and their impacts were socially patterned and evaluations should seek to identify which groups in the population had experienced the benefits and harms of a given intervention.


The impact of investment in infrastructure was discussed. It was noted that the Sustainable Travel Towns programme cost £10 per person per year. In Copenhagen £40 per person per year was invested in infrastructure and they had far lower rates of car use. It was suggested that investment was related to impact. Following the evaluation of the Sustainable Travel Towns, one estimate suggested an investment of £20 per person per year in "smarter choice" measures was needed. It was noted that road user charging does not cost money but rather creates revenue, though this is only one form of intervention, which may not be effective in isolation.

It was noted that not only do other European countries spend more but that they have been spending more consistently for longer. That had not happened in the United Kingdom; when something had been shown to work, it had often been stopped. It was suggested that there was a danger in comparing the United Kingdom to Europe, as levels of car use in Europe would not be matched quickly. There was considered to be large potential for change in the United Kingdom but change would take time.

346   Public health: ethical issues, op. citBack

347   Health Committee, 3rd report (2008-09): Health Inequalities (HC Paper 286) Back

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