The spectral analysis of road transportation cycle fluctuation

Correct understanding of the characteristics of road transportation cycle fluctuation is very important for its sustained and stable development. The paper put forward to validate the periodicity of the road transportation fluctuation by using spectral analysis. According to Fourier progression, the road transportation indicators can be expanded as the sum of several sine and cosine functions with different frequencies. The value of power spectrum density and standardized power spectrum density function of road transportation indicator time series is estimated with Tukey-Hanning windows truncation Fourier transformation. In the end, the presented theory and means are employed to do demonstrative research on road freight volume, freight turnover volume, passenger volume and passenger turnover volume. The result indicates that there are 6~7 years medium wave and about 3 years shortwave during the development of road transportation.