Technique for judging tire width and tread of vehicle

A method of judging the tire width and tread of a vehicle, comprising the steps of:

• (a) scanning a state of each individual contact point of a switch array in a predetermined cycle, renewing and storing the state, the switch array including common contact points lying across a vehicle pass way, the common contact points being formed of a strip-shape conductor, and a plurality of equidistant individual contact points, disposed on a plane parallel to and adjacent to a plane of the common contact points and having a predetermined distance therebetween, the individual contact points coming into contact with the common contact points when treading pressure is applied thereto;
• (b) reading state data of each individual contact point stored at step (a), and judging if there is an individual contact point turned on;
• (c) judging if a vehicle has been detected when it has been determined that there is an individual contact point turned on at step (b);
• (d) judging if an axle has completely passed when it has been determined that vehicle has been detected at step (c);
• and
• (e) repeating from step (b) when it has been determined that the axle has not passed completely at step (d), and judging the tire width and tread on the basis of the state of the individual contact points turned on when the axle has passed completely.