Is it really a stupid idea? The counterfactual check

Proposals for unconventional policies often receive a lot of negative reactions, from media, citizens, politicians, interest groups, etc. The counterfactual check may be a simple method to explore if such policies are really a bad idea. In a recent paper on growing support for controversial policies, we briefly discussed the idea of asking people whether the counterfactual of a controversial policy proposal would be a good idea (Van Wee et al., 2023). We gave the example of the proposal to convert a two-way street into a one-way street. I live in Amersfoort, a medium-sized city (almost 161,000 inhabitants on January 2023) in the Netherlands, in a 1930s neighbourhood (i.e. the Leusderkwartier). Some years ago, the local municipality suggested to convert that road in that neighbourhood to a one-way street for motorised traffic (not for cyclists), for reasons of safety and liveability. The road is frequently used by cyclists, including 12–18-year-old high school students. In the street where I live, many people had a poster behind their window stating the following: “keep the Leusderkwartier accessible”. I did not have such a poster. One of my neighbours asked why. I explained that I was not sure if I thought it was a bad idea. He responded telling me that I certainly must think it was a bad idea. I asked him why. He responded saying that the idea was ridiculous because we then would have to take a detour driving in “opposite direction”. I said he was right, that of course that would mean a (small) detour, but also that it would become a safer, quieter and consequently more attractive street. I asked him: suppose the street would always have been a one-way street, as the local municipality now suggested. And suppose the proposal was to make it a two-way street. Would he then think this would be a brilliant idea? I hypothesised that he and many others would show a poster behind their window with the following text: “keep the Leusderkwartier safe and liveable”. He responded that he would not know if he would support the counterfactual change, and that this conversation made him think. Another example. In 2022, I was at an OECD (Organisation for Economic Co-operation and Development) Round Table meeting in Paris. One of the participants told me about the, in his opinion, ridiculous idea of converting the Route Periferique, an urban motorway surrounding central Paris, into a park with a cycle lane. I asked him why he thought that was a ridiculous idea. He indicated that the traffic intensities show that we need the Route Periferique. I asked him: suppose the Route Periferique would have been a park with a cycle lane for decades or even a century, would he support the idea of now converting it into an urban motorway, comparable to the current situation? A long silence occurred, followed by “I do not know”. I also asked him: what would he think would happen if Paris