Collision avoidance system

A collision avoidance system, comprising:

• an onboard acquisition unit provided in a vehicle traveling on a road and configured to acquire state quantity data indicating a state quantity of a pneumatic tire of the vehicle, the state quantity including an amount of wear of the pneumatic tire, and the pneumatic tire including:
• a first mark provided on a surface of a tread portion that comes into contact with a road surface, and a second mark embedded in tread rubber of the tread portion;
• an onboard transmission unit provided in the vehicle and configured to transmit the state quantity data acquired by the onboard acquisition unit to a data acquisition roadside device installed on the road;
• an abnormality determination unit configured to determine whether or not the amount of wear is abnormal;
• and
• a management device including:
• a data acquisition unit configured to acquire the state quantity data from the data acquisition roadside device;
• a data storage unit configured to store the state quantity data acquired by the data acquisition unit;
• a data distribution unit configured to distribute the state quantity data determined as abnormal by the abnormality determination unit;
• a following vehicle acquisition unit provided in a following vehicle traveling behind the vehicle and configured to acquire amount of wear data indicating the amount of wear of the pneumatic tire of the vehicle, the following vehicle acquisition unit including a camera configured to acquire images of the first mark and the second mark, and is configured to estimate the amount of wear of the pneumatic tire on the basis of image data representing the acquired images;
• and
• a following vehicle transmission unit provided in the following vehicle and configured to transmit the amount of wear data acquired by the following vehicle acquisition unit to the data acquisition roadside device;
• wherein the data distribution unit is configured to distribute the amount of wear data determined as abnormal by the abnormality determination unit to at least one of the vehicle and a second following vehicle traveling behind the following vehicle.