The light is red: Uncertainty behaviours displayed by pedestrians during illegal road crossing

•Hesitation occurs when a pedestrian slows down or stops his/her crossing movement then abandons by returning to the kerb or accelerates to cross.•The uncertainty time of pedestrians is longer in Japan than in France.•Hesitation seems to occur in Japan when a pedestrian follows others already crossing against the red light.•No effect of age or gender on the pedestrian uncertainty behaviour. Road accidents involving pedestrians are a reality of urban life. Pedestrian risk is now well known and documented from the perspective of drivers. However, pedestrian behaviour plays a central role in road accidents, notably in terms of illegal road crossing at signalized intersections. This study focuses on pedestrians crossing illegally at a signal light, and specifically investigates uncertainty behaviour, also referred to as hesitation, which occurs when a pedestrian slows down or stops his/her crossing movement then (1) abandons the crossing by returning to the kerb or (2) accelerates to cross the road more quickly. We sought to understand the causes of this behaviour in France and Japan, two countries where interesting differences have already been demonstrated in the way pedestrians behave. The results show a longer period of uncertainty for pedestrians in Japan compared to France. Japanese pedestrians also hesitated longer when they were alone. This study demonstrates a tendency to speed up if there are a number of pedestrians already crossing the road, but abandoning behaviours were more frequently observed than acceleration. This study confirms that pedestrians may misevaluate the moment to cross and hesitate when they realise that they have made a mistake, thus increasing the risk of an accident. These results could help to find solutions that prevent illegal and dangerous road-crossing behaviours.