In the proposed system, it is applied by the technologyof Wireless Access in Vehicular Environment/Dedicated ShortRange Communications (WAVE/DSRC), radar installed againstthe intersection, and Global Positioning System (GPS) of vehiclesto access vehicle speed, latitude, longitude, direction, and otherinformation immediately. The above information will be gatheredinto DSRC On-Board Equipment (OBE) of the vehicle around theintersection. Meanwhile, it will provide real-time transversealerts to the vehicles. In this paper, based on the field trial, it isrevealed that the proposed system can warn the driver promptly,improve traffic safety, and avoid unnecessary false alarms.