Objective Luchemos por la Vida, non-governmental and non-profit organisation, that studies and works in Argentina to prevent traffic accidents, decided to observe systematically the pedestrians' behaviour in avenues and streets of a city, Buenos Aires, to identify the most common risk behaviours and to define a massive awareness campaign to change the beliefs, attitudes and behaviour of this group, the most vulnerable in the traffic system. In the city of Buenos Aires, 44% of the people who die in the traffic are pedestrians.

Methodology We selected representative samples of crossroads in the city and we registered observations of the behaviour of 3685 pedestrians. This information was complemented with focused interviews to know the motivations of the observed conducts.

Results From the different observations carried out, we found that, on average, only 6% of the pedestrians cross in the correct way on street corners with traffic lights and without traffic lights, a very low rate of the traffic law observance. The focused interviews provided the most common motivations for these conducts.

Discussion and Conclusions The results confirm what the traffic psychology explains as the chosen risk. Facing a low perception of the risk for probabilities learning and the perception of benefiting from crossing improperly, people chose this behaviour.

Based of the obtained results, we decided to develop an awareness campaign aimed at pedestrians, young and adult people, with the objective to increase the risk perception and to propose measures of self-protection.