| 摘要 |
PROBLEM TO BE SOLVED: To provide a congestion alarm device and a congestion alarm system that alarm drivers of traffic congestion by placing congestion alarm devices on the road according to need in response to an unexpected accident and a hasty construction.SOLUTION: A plurality of congestion alarm devices are placed along a road in the order of an identification number given in advance from the smallest number from a downstream side toward an upstream side of the flow of vehicles traveling on the road. Each congestion alarm device comprises: a speed sensor for detecting the speed of a vehicle traveling on the road; an indicator for indicating the state of traffic congestion; a radio unit for communicating with other congestion alarm devices by radio; and a control unit for indicating, on the indicator, indication information corresponding to the state of traffic congestion corresponding to a change in the speed of the vehicle detected by the speed sensor, or the state of traffic congestion received from a congestion alarm device with a smaller identification number next to and at the downstream side of the congestion alarm device by the radio unit, and for transmitting the state of traffic congestion to a congestion alarm device with a larger identification number next to and at the upstream side of the congestion alarm device through the radio unit.SELECTED DRAWING: Figure 1 |
