Research on a Map-matching Method for a GNSS-based ETC System

Abstract

This paper describes a new definition of a map on the on-board unit (OBU) side as well as a new map-matching method for a global navigation satellite system (GNSS)-based Electronic Toll Collection (ETC) system. Key points and links are defined on a new map according to the highway design of an urban area in China in order to meet the needs of the GNSS-based ETC system. A new map-matching algorithm is proposed based on this map definition. The GPS search area changes with the running speed of the vehicle during the map-matching process. The proposed method first matches GPS data to the key nodes on the map instead of using links. Next, it matches the key exit, entry and passing links according to the charging status. Finally, it identifies the links by link property and adjacency relation to avoid interference from nearby vehicles. At the end of the paper, the performance of the proposed system in the experiment is evaluated, and other methods to improve the accuracy of map-matching are discussed.