| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect reverse traveling in a unidirectional road and to surely warn a driver of reverse traveling when reverse traveling is detected. <P>SOLUTION: A simplified ETC road-side radio device 200 is installed at a point branched from a main line in the vicinity of an entrance to SA/PA or the like. When a vehicle in which an ETC in-vehicle unit 400 is mounted passes near the entrance, the ETC in-vehicle unit 400 and the simplified ETC road-side radio device 200 start communicating, and the simplified ETC road-side radio device 200 receives WCN (identification information) from the ETC in-vehicle unit 400 and outputs the WCN to a reverse traveling detection device 100. When the same WCN is inputted twice and a difference between both input times is equal to or longer than a detection start time (time for avoiding erroneous detection under traffic jam) and equal to or below a re-enter time (time for avoiding erroneous detection caused by re-entering SA/PA), the reverse traveling detection device 100 determines occurrence of reverse traveling and outputs reverse traveling detection to a reverse traveling warning device 300. The reverse traveling warning device 300 issues a warning notifying reverse traveling and warns a driver of reverse traveling. <P>COPYRIGHT: (C)2012,JPO&INPIT |
