Evaluation of navigation performances of GPS devices near interchange area pertaining to wrong-way driving

Based on past studies, exit ramp terminals are the common locations for drivers to enter a physically separated highway in the wrong direction. Currently, many drivers, especially nonlocal drivers, often rely on voice-guided navigation apps and Global Positioning System （GPS） devices to navigate their routes on and off freeways. A few studies have reported that GPS devices sometimes give drivers wrong information and cause wrong-way entry into a freeway, especially at some confusing interchanges, such as partial cloverleaf and compressed diamond interchanges. The access points located close to exit ramps may also cause a problem for GPS devices in sending accurate voice-guidance. It is unknown if current GPS devices are capable of properly informing drivers regarding turning movements in advance of exit ramp terminals at some common interchanges. The objective of this study is to evaluate the most commonly used GPS devices/navigation apps to identify existing problems and their potential for reducing wrong-way driving （WWD） incidents at interchange terminals. Field experiments were conducted at 10 common freeway interchanges or interchanges with nearby access driveways in the state of Alabama. Results show that most GPS devices have difficulty in providing correct guidance when the spacing between an access point and an exit ramp is less than 300 feet. Our comparison of five different GPS devices used on the same routes reveals that navigation apps have more limitations in guiding drivers than stand-alone GPS devices. Recommendations are offered to help GPS mapping companies improve their devices or add new features to reduce the occurrence of WWD.

Relay navigation strategy study on intelligent drive on urban roads

In order to solve navigation problem of intelligent vehicle driving on urban roads and to achieve the navigation in intersection area, intersection transition area and section area. The relay navigation strategy and algorithm can solve the navigation problem of intelligent vehicle driving in typical urban roads such as intersection area, intersection transition area and section area, realizing seamless handover among different typical areas. Bezier curve function model was introduced to different typical areas, which solved the self-adaption recognition problem in different typical areas and revised positional accuracy with the help of cloud computing positioning service. In order to explain the strategy implement, an instance based on the strategy was adopted. Instance analysis indicates that as for the navigation problem in intersection area, intersection transition area and section area, if the relay navigation strategy is utilized, the self-adaption recognition problem in different typical areas can be handled. Based on the relay navigation strategy, the drive of intelligent vehicle on urban roads can effectively solve the self-adaption recognition problem in different typical areas in urban and further solve driving problems of intelligent vehicle of the same category in urban roads.