To provide an inter-vehicle distance
warning system for preventing a detection omission of a preceding vehicle and further appropriately issuing a warning of an inter-vehicle distance.SOLUTION: An inter-vehicle distance
warning system 10 includes: inter-vehicle distance warning devices installed in vehicles 20; and a
server 100. The
server 100 notifies a vehicle of an inter-vehicle distance warning notification when necessity of warning on an inter-vehicle distance is determined based on position information of a plurality of vehicles. The inter-vehicle distance warning device includes: an inter-vehicle distance warning acquisition section for acquiring the inter-vehicle distance warning notification; and a determination section
information acquisition section for acquiring determination section information which indicates a determination state of an inter-vehicle distance by an on-vehicle
machine. The inter-vehicle distance warning device includes: a warning state determination section for determining whether first
processing to issue a warning on the inter-vehicle distance is being executed; and a determination state determination section for determining whether second
processing to determine the inter-vehicle distance is being executed. The inter-vehicle distance warning device includes an inter-vehicle distance warning control section to which the inter-vehicle distance warning notification is transmitted and which controls issuing of the warning when neither the first
processing nor the second processing are being executed.SELECTED DRAWING: Figure 1