Hong Kong team develops GPS-augmentation system to cope with multi-level road networks


A team of researchers at the University of Hong Kong (HKU) has won international recognition for developing a navigation system that provides accurate positioning information on complex multi-level road networks.

Multi-level road networks such as flyovers and overpasses are built in large cities to solve traffic congestion, but instant and correct identification of the road level that a vehicle is driving on is crucial to make driving easier and safer.

Drivers relying on standard GPS navigation that accidentally drive onto a flyover with intention of traveling only at ground level often face this problem. The GPS navigation system does not realize that the vehicle has entered a wrong level and continues to give instructions as if it were on the ground, and will only begin to redirect to a new route once the error becomes apparent. These positioning problems often create confusion and ‘motorway anxiety disorder’ for drivers, making them more prone to accidents.

A research team led by Professor Anthony Yeh Gar-On at HKU’s Department of Urban Planning and Design has developed a novel solution to this longstanding GPS navigation problem by instantly identifying whether a vehicle has entered a flyover or is still at ground level.

The ‘Angle Difference Method’ developed by the team compares the inclination angle of a vehicle and angles of different road levels stored in a Transport GIS (Geographic Information System) to determine whether a vehicle has entered the ramp of a flyover or is still at ground level.

The system uses an ordinary smartphone that can be put anywhere in the vehicle, at any angle, with a plugged in or installed onboard diagnostic (OBD) device. The system provides a simple and inexpensive solution to warn drivers instantly when they have accidentally entered a wrong road level. Tests show the system has a level-identification accuracy of 100%.

The innovation won a gold medal award at the Geneva International Exhibition of Inventions in April, and has also received a US patent and an International PCT patent. The team is currently discussing with global GIS and vehicle navigation operators on potential applications and commercialization of the new system.

“The invention provides an innovative, simple and inexpensive method to overcome the long existing vehicle navigation problem that many people have tried to solve since GPS was used over 20 years ago by determining instantly whether a vehicle has entered a flyover or is still on the ground level,” noted Professor Yeh.

“The research team will further apply this Angle Difference Method to the navigation of automatic cars.”

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Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).