Intervention.
When you're aiming to enhance customer engagement, improve employee performance, or drive public health initiatives.
SoMoCo’s intervention design service exists to help you achieve meaningful, lasting behavioural change.
The following case study is a great example of this.
Case Study :
The 20 Effect: Insight-Led Strategies for Speed Reduction.
Liverpool City Council.
Summary
This case study demonstrates how SoMoCo leveraged behavioural science to create what many regard as the most effective 20mph speed limit campaign in UK history. By addressing behavioural barriers, mobilising community resources, and shifting the narrative away from local politicians, SoMoCo significantly increased public support, reduced collisions, and ensured widespread compliance.
One of the campaign’s most impactful strategies involved overcoming the limited police resources available to enforce the new speed limits. By amplifying the perception of police presence, making it appear more robust than the actual on-the-ground resources, SoMoCo effectively leveraged police support in a manner that proved hugely effective.
The entire scheme generated a 1,234% return on investment (ROI), turning a £1.52 million investment into an £18.8 million return.
A three-year study of the initiative revealed a 3.5mph average speed reduction—more than double the target—and a reduction of 191 collisions per year, far surpassing the goal of 54. The campaign also achieved the lowest rate of objections to Traffic Regulation Orders (TROs) among UK authorities.
Liverpool’s 20mph scheme, backed by SoMoCo’s strategies, is now a benchmark for similar initiatives across the UK and SoMoCo became an advisor to many UK cities.
Context
Liverpool City Council aimed to implement 20mph speed limits on 70% of its roads. The key objectives were to increase public support before the introduction of Traffic Regulation Orders (TROs) and achieve actual speed reductions post-implementation.
Merseyside Police expressed concerns about their enforcement capacity, raising fears that insufficient policing would lead the public to disregard the new speed limits. Previous UK schemes had faced significant public opposition and poor compliance.
Behavioural Analysis
SoMoCo identified key behavioural barriers and opportunities in achieving public support and compliance with Liverpool's 20mph speed limits.
Firstly, Social Proof & Affinity Bias offered a chance to shape new norms around the 20mph limits, leveraging relatable local stories to foster adoption. The absence of an established norm provided a window to promote desired behaviours through community-driven narratives.
The Fundamental Attribution Error was evident, with residents believing that speeding was an issue caused by others, while justifying their own speeding as exceptional or necessary. SoMoCo aimed to correct this by reframing the narrative to encourage every driver to take personal responsibility.
The Fairness Principle revealed that public cooperation with the speed limits hinged on the perception of equal enforcement by authorities. The community wanted reassurance that the police were doing their part, without which compliance would likely suffer.
Finally, Children as Motivators played a significant role. Messaging that highlighted the protection of children resonated more deeply than abstract benefits like improved air quality. These messages were particularly effective in motivating behavioural change by tapping into the tangible concerns of residents.
Strategy
SoMoCo developed a campaign strategy that shifted the narrative from political leaders to local influencers within the community. They mobilised far reaching support, co-designing micro campaigns and activities with various stakeholders, including residents’ groups, schools, businesses, hospitals, and public figures to demonstrate public support and anticipated benefits arising from the new limits.
SoMoCo addressed the fundamental attribution error by shifting the narrative from blaming 'others' for speeding to encouraging every driver to take personal responsibility for the new speed limits. This was achieved through interventions like "Kids Court," where speeding drivers were confronted with the real-life consequences of their actions by speaking directly with children about their vulnerability in a powerful and moving encounter, later expanded through roadside interventions using video.
This personal and emotional engagement helped drivers recognise that they were not exceptions, and their behaviour directly impacted the safety of their community, fostering a sense of individual responsibility.
The campaign also creatively engaged Merseyside Police, SoMoCo created the perception of greater police involvement by strategically amplifying every instance of police activity related to the 20mph campaign. They ensured that the police presence was prominently featured in press stories, social media, and public communications. This approach made it seem as though the police were heavily involved in enforcing the new speed limits, even though their actual on-the-ground resources were limited. The key was to create a sense of vigilance and enforcement that increased the public’s perception of risk and compliance with the new speed limits.
SoMoCo amplified coproductions with communities through effective use of local, regional, and national media, alongside word of mouth and social channels to amplify community support for the 20mph scheme. Imaginative and engaging stories were widely shared. By highlighting these narratives, SoMoCo leveraged social proof, creating the impression that the 20mph initiative was widely accepted and supported, which encouraged broader public buy-in.
Implementation
The campaign was launched across Liverpool, with strong community participation and extensive media coverage.
Public engagement activities were tailored to local contexts, ensuring wide-reaching involvement.
Results & Impact :
Result
Secured strong public support
Achieved the lowest rate of objections to Traffic Regulation Orders (TROs) of any UK unitary authority 20mph scheme, significantly reducing the time and costs associated with managing formal objections.
Result
Anticipated speed reduction: 1.5 mph
Achieved speed reduction:
3.5 mph
Verified through a 3-year post-intervention study conducted by the local authority.
Result
Target:
54 fewer collisions annually
Achieved:
191 fewer collisions annually
Outcomes confirmed by a 3-year post-intervention study conducted by the local authority.
ROI
Return on Investment: 1,234%
Implementation cost: £1.52m
Savings achieved: £18.8m
The behavioural interventions delivered by SoMoCo were pivotal in helping the local authority achieve this outstanding ROI.
Impact
The Liverpool 20mph scheme, supported by SoMoCo's behavioural interventions, is recognised as the most effective of its kind in the UK.
It became a national model, inspiring other cities. SoMoCo subsequently supported successful implementation in major cities across the UK and Northern Ireland.
Testimonial :
“The 20 Effect project was about giving the streets back to the neighbourhoods, encouraging walking and cycling and making it feel more like a residential place rather than just a place for cars. I’m proud of what we achieved together and the fact that this behaviour change campaign has been held up as a beacon nationally and by the likes of 20s Plenty. The approach SoMoCo used is one that other cities in other places should be following in terms of getting the public buy in, that changes hearts and minds.””
JAYNE BLACK, HEAD OF HIGHWAYS, CHESTER WEST AND CHESTER
