Peter Cramton and colleagues suggest that dynamic road pricing could be a solution to traffic problems (Nature 560, 23–25; 2018). As social scientists, we argue that getting drivers to change their behaviour might not be so simple, because the behaviour does not depend only on prices.
For instance, drivers tend to stick with their usual routes, departure times and destinations. Many would be reluctant to adapt their trips to a road-pricing scheme that fluctuates across time and place according to traffic conditions, because this requires too much mental effort. And charges would need to be prohibitively high to persuade them to give up the convenience, independence, flexibility, comfort and speed of using their cars.
Neither can public support for road pricing be assumed. It was blocked in Manchester (2005) and Edinburgh (2007) in the United Kingdom, in the Netherlands in 2010, and in Copenhagen in 2012. Pricing policies need to be seen as fair to be acceptable, which is more likely if they protect the environment and future generations. Such psychological motives are rarely considered in economic models and in public and policy debates.
More interdisciplinary research into the causes of traffic problems is necessary for designing socially feasible policy solutions. For example, public support could be grown by communicating the extent to which such schemes would meet their objectives and how drivers would benefit.
Nature 564, 39 (2018)