Research has shown that older pedestrians have more difficulty making road-crossing decisions than younger adults, which presents an opportunity for vehicle-to-pedestrian (V2P) communication to assist older adults’ street-crossing decisions. This study developed an application (app) for smartphones generating visual, haptic, and auditory  permissive alerts (safe to cross) and prohibitive warnings (not safe to cross) in a virtual street-crossing environment. A between-subjects study (i.e., different people test each condition) was completed with 66 participants ages 65-84 to understand the effects of these alerts and warnings. Each user’s brisk walking speed was considered to determine whether it was safe to cross the street in a stream of traffic. Participants’ behavior under three different conditions were studied: i) permissive where the participants held a mobile phone and received alerts telling them when it was safe to cross, ii) prohibitive where the participants held a mobile phone and received warnings telling them that it was not safe to cross, iii) control where the participants held a mobile phone throughout the road-crossing session but did not receive any alerts.