In [1], it was shown that the standard version of the spatio-temporal ray optics (STRO) can only be used in the case of fairly weak frequency dispersion of the medium and cannot describe the dispersive refraction effect related to the transverse frequency modulation and having geometricoptical spatial and temporal scales. In the present paper, we propose a simpler way of deriving the revised spatio-temporal ray equations which are based on the model of a field with smooth transverse inhomogeneity of the amplitude in the form of an Airy function.