A connected vehicle traffic safety system comprises a traffic signal controller and a roadside unit (RSU) located at a one-way traffic lane for avoiding crashes with vehicles of wrong-way drivers by issuing warnings for wrong-way violations. The traffic signal controller is configured to operate a traffic signal. The traffic signal is facing a wrong-way traffic and is set to dwell permanently in a RED signal phase. The one-way traffic lane is configured as a signalized intersection with a wrong-way approach that is programmed as a traffic signal phase dwelling in RED. The roadside unit (RSU) is configured to transmit a Signal Phase and Timing (SPaT) indication for the RED signal phase. A first Onboard Unit (OBU)-equipped vehicle having an Onboard Unit (OBU) that is configured to calculate a RED light violation based on at least one of vehicle location data, direction heading data, and speed data provided from the first OBU-equipped vehicle and the SPaT indication of the RED signal phase to detect the first Onboard Unit (OBU)-equipped vehicle as a wrong-way vehicle.