This SAE Recommended Practice applies to both Original Equipment Manufacturer (OEM) and aftermarket ITS message-generating systems for passenger vehicles and heavy trucks. The recommended practice describes the method for prioritizing ITS in-vehicle messages and/or displayed information based on a defined set of criteria. Each criterion has a fixed number of levels that are used to rate/rank a given message or information item to determine its prioritization value. The prioritization value is used to determine the priority in which simultaneous, or overlapping, in-vehicle messages are presented to the driver.