关键词：驾驶辅助系统；电子设备；全球定位系统；导航设备
摘 要：The global positioning system (GPS) market is a fast changing, highly competitive market. Products change frequently as they try to provide the best customer experience for a service that is based on the need for real-time data. Two major functions of the GPS unit are to correctly report traffic jams on a drivers route and provide an accurate and timely estimated time of arrival (ETA) for the driver whether he/she is in a traffic jam or just following driving directions from a GPS unit. This study measures the accuracy of traffic jam reporting by having Personal Navigational Devices (PNDs) from TomTom and Garmin and phone apps from TomTom, INRIX, and Google in the same vehicle programmed to arrive at the same destination. We found significant differences between the units in terms of their ability to recognize an upcoming traffic jam. We also found differences in how well the devices responded to jams when driving on surface streets versus highways, and whether the jams were shorter or longer in length. We see potential for auto manufacturers to employ real-time traffic in their new vehicles, providing potential growth for real-time traffic providers through access to new vehicles as well as the aftermarket.