Background: Pedestrians crossing decisions are set by explicit indications supplied from road signals and markings, drivers’ behavioral cues (e.g., eye-contact, gestures and postures), but also implicit communication cues such as vehicles’ speed and relative distance when the situation is ambiguous. Yet, previous work reported difficulties for children and older adults to make safe street-crossing decisions, due to impaired abilities to estimate speeds and gaps of oncoming vehicles. In this context, we aimed at investigating the impact of an external vehicle display indicating oncoming vehicles’ speed on pedestrians’ risky behavior. Method: Participants were recruited according to three categories of age, namely, children (9-14 years old), young adults (18-40 years old), and older adults (from 75 years old). Participants were asked to observe real-world videos of oncoming vehicles in a straight road using a pedestrian view in front of a crosswalk. Using a between-participant design, participants could be given the effective speed of the oncoming vehicle through an external vehicle display or not. The speed of the lead vehicle (30 km/h vs. 50 km/h) was manipulated within-participant. Participants’ task consisted in indicating whenever they felt insecure to cross the road given the vehicle’s state on the video by pressing a key. Our measure was the reported time of criticality, that is, from the beginning of the video, the time at which participants reported feeling insecure to cross in front of the leading vehicle. Data collection is ongoing and will be presented at the conference.Expected results: For each trial, a vehicle’s time to collision was computed, given the actual speed of the leading vehicle and its relative distance from the collision point (i.e., the center of the crosswalk). We predict that young adults’ reported times of criticality will be comprised before the time to collision with the oncoming vehicle regardless of the experimental condition as their ability to estimate the state of the vehicle is not deficient. By contrast, we predict that children and older adults will benefit from additional information supply, leading to safer reported time of criticality (i.e., before the vehicle’s time of collision) when the effective speed of the oncoming vehicle is presented through an external vehicle display.Discussion: The results will be discussed with regards to the imminent arrival of automated vehicle in the road traffic. In particular, drivers’ behavioral cues will no longer necessarily be present with this kind of automation and pedestrians will have to rely on information sent by the automated vehicle in order to make safe crossing decisions. This issue is of primary importance for vulnerable road users. To give speed information through an external vehicle display on existing standard vehicles can be a first step to make pedestrians accept this sort of apparatus on future automated vehicles. Moreover, as opposed to many available prototypes of automated vehicles indicating whether the pedestrian can cross or not, to give speed information can be regarded as a universal data that can be simultaneously processed by various road users.