DRIVING CHARACTERISTIC DIAGNOSING SYSTEM AND DRIVING CHARACTERISTIC DIAGNOSIS DEVICE

PROBLEM TO BE SOLVED: To provide a driving characteristic diagnosis system and device that can grasp a possibility of a rear-end collision accident on a basis of driving characteristics.SOLUTION: When sudden braking of an own vehicle is detected, the vehicle obtains information identifying a preceding vehicle, which is a vehicle traveling ahead of the own vehicle, and transmits to a server device information identifying the own vehicle as information indicating a vehicle that has braked suddenly and information identifying the preceding vehicle as information indicating a vehicle traveling ahead of the vehicle that has braked suddenly. The server device stores each vehicle's driving characteristic data, which indicates driving characteristics of each vehicle and has a first characteristic value corresponding to the number of times of sudden braking and a second characteristic value corresponding to the number of times of sudden braking of a following vehicle. When the server device receives information from a vehicle, it adds a first addition value to the first characteristic value of the driving characteristic data corresponding to the vehicle that has braked suddenly and adds a second addition value to the second characteristic value of the driving characteristic data corresponding to the preceding vehicle.