Yesterday Chris Grayling announced a consultation on green number plates as part of efforts to increase ownership of zero emission vehicles and cut Britain’s carbon emissions.
The idea, already implemented in countries like Norway, Canada, and China, would make electric and hydrogen cars much more visible on our roads.
We at the Behavioural Insights Team support and provided early advice on the plans. We think green number plates would increase awareness and encourage uptake of clean vehicles in a number of ways.
Green plates would attract our attention and make clean vehicles identifiable
Our attention tends to be drawn to anything novel or personally relevant. We’ve found this to be the case in trials on using handwritten messages on the outside of envelopes, for example. Most zero emission vehicles are currently not easily distinguishable from conventional cars, meaning we may underestimate how many are actually out there.
Green number plates—an unusual and novel sight on our roads, with added environmental connotations—would likely have a similar impact and make zero emission vehicles more noticeable.
We like to follow the trend
The number of people buying zero emission vehicles has increased over the years, but we may still underestimate the total figure.
By increasing their visibility on the roads, green plates could readjust our perception of the norm. If we think more of our fellow road users are buying and driving clean cars, we in turn might be more likely to buy them ourselves, as we have a tendency to conform to what we think people around us are doing.
Even if overall numbers remain low compared to conventional vehicles, evidence suggests that changes in prevalence make us more inclined to join an emerging trend.
An added ‘green’ signalling bonus
Whether we like to admit it, our choices around buying clothes, food, or other products are often made with other people in mind. We like to express our identity and ‘virtue signal’ to those around us. This may make green number plates particularly effective for certain groups.
For example, those of us who care about the environment often make explicitly ‘green’ choices in the products we buy and use, particularly when those choices are visible to our peers. One paper has even described this as the ‘Prius halo’ effect. By making zero emission vehicles more visible, we’re giving people another way to display their environmental credentials to their peers, which may encourage their purchase.
We welcome this consultation on green number plates and were pleased to see the positive reaction in yesterday’s media. While this is a positive step, we’d also recommend testing green plates alongside other interventions based on behavioural insights. Millions of us renew our car tax online each year—what about a timely prompt to book an electric car for a test drive? Or pairing green number plates with incentives such preferential parking in city centres or green lanes on major roads. Alongside a broader package of policies we think this has real potential to reduce emissions and improve air quality in our cities.