top of page
  • Writer's picturenovanudgeclub

Highway to Nudge: How to reduce car accidents

Updated: May 24, 2021


The symbolic representation of the Nudge concept is related to the cover of Cass Sunstein and Richard Taller’s book Nudge, in which a mother elephant is nudging her baby, through a push, to keep on walking. An action like the one we do when our car seems not to be able to turn on, and so we give it a little push for it to start moving. Nevertheless, the relationship between nudge and automobilist vehicles does not end here, in fact, behavioural economics can and is being used to promote safety for drivers and to diminish traffic accidents.

The magnitude of the problem

Road traffic crashes are the cause of death of approximately 1.35 million people per year, being the leading cause of death for children and young adults aged between 5 and 29 years old. Car accidents cost most countries 3% of their gross domestic product, on average, besides the priceless loss of lives. That being said, the great question we want to study and consequently answer is how can nudge act to reduce the number of accidents on our roads, avoiding deaths, and maximizing security.

Evidence of possible solutions

In Philadelphia, in 2008, a possible answer experimented. The strategy was to paint fake realist speed bumps in some specific roads, to slow down the pace at which drivers used to pass through it. This substitute of speed bumps aims to create the same effect as them, with a reduced cost in comparison, painted bumps cost 500$, whether real one amount to 2000$.

This artistic solution is not only about reducing costs, it also does not impede water flow and is not a threat to ambulances or other vehicles seeding by emergency. Nevertheless, on the other side of the coin, this slow down graffities lose their efficiency when drivers get used to circulating through those roads and see them, which can lead to the inverse consequence of promoting usual costumers of the public good to drive faster, since sprinting through a fake speed bump would not cause the same physical damages as if it were done through a real one.

Another available option consists of a noise nudge provided by special coating strips on the asphalt. Most Portuguese people are familiar with the circulation through 25th of April Bridge, in which there are special strips on the edges of the road, producing a shrill noise when a vehicle drives by, to alert the driver for the danger of being on the verge, at few centimetres of a dive into the Tagus river. This technique is similar, nudging by producing a shrill sound to alert drivers, but in this case, the noise is only activated when vehicles are circulating at a certain speed or above it. These distinct coating strips are harmless to the cars, leading to no depreciation of their materials.

Another example comes from the United Kingdom. Essentially, the government used an environment-friendly option. In Norfolk City, trees have been planted at an increasing distance by the margins of the road when approaching the village. This technique will create a visual illusion, leading drivers to think they are at a higher velocity, reducing it as they get closer to Norfolk. The choice regarding trees will also have positive environmental repercussions.


To sum up, behavioural economics has multiple uses to nudge our society into a better outcome and traffic disasters are another example in which those theories can get a practical form, considering monetary and environmental costs, improving safety in our roads, for drivers, for passengers and even for pedestrians.


Afonso Gonçalves – Research Analyst


565 views0 comments

Recent Posts

See All


bottom of page