The apparatus acquires acceleration data in time series at a fixed position of a tire while a vehicle having the tire is traveling on a road surface, obtains a spectrum of the acceleration by subjecting the acquired time series acceleration data to frequency analysis, and detects a peak value of the spectrum of the acceleration in a frequency range of 500 Hz-1500 Hz. The apparatus evaluates a degree of a safety in traveling of the vehicle according to the detected peak value. The acceleration data is acquired by an acceleration sensor mounted on the fixed position of the tire.