An on-vehicle device includes: a driving support device to receive driving support information from a driving support server and execute a predetermined process for driving support; a sub driving support server including a driving support server function subset and receives sensor data from an external sensor and output a subset of the driving support information; a first switching device giving the subset of the driving support information to the driving support device in response to interruption of reception of the driving support information from the driving support server; and a second switching device configured to give the driving support information from the driving support server, instead of the subset of the driving support information from the sub driving support server, to the driving support device in response to recovery of the reception of the driving support information from the driving support server.