VEHICLE SENSING SYSTEM

PROBLEM TO BE SOLVED: To deal with the deviation of a background level from a true value.SOLUTION: A vehicle sensing system includes a determination section 32 for determining the presence/absence of a vehicle by defining a value based on a difference between an input level obtained from a detection section 2 for detecting a temperature in a monitoring area A on a road R and a background level based on a temperature level of the road R as a comparison value and comparing the comparison value with a threshold value. The system further includes a background level learning section 33 for performing learning processing of the background level on the basis of the input level while the absence of a vehicle is determined; and a learning control section 35 for controlling execution or stop of learning processing of the background level in accordance with the comparison value while the absence of a vehicle is determined.