In this paper, we use maximum track length approach depending on track diameter-length (D-L) correlation as another way to estimate directly from empirical measurements of the track diameters or lengths without resorting to other methods. The lengths of the tracks have been extracted using the (D-L) correlation which relied on the measurement of the opening’s diameter of the etched tracks, in addition to using the Track-Test program . 241Am (1μCi) source was used to irradiate the plastic detector CR-39 with alpha particles of energies of (3.5-5.3) MeV by means of normal incidence. The irradiated detectors were treated by a chemical etchant for distinct intervals of time using an aqueous NaOH solution of 6 N preserved at temperature (70±1) . An empirical formula was applied to calculate . The formula relies on two parameters, the maximum length of the track and its saturation time . We have seen that the magnitude of is equal to 1.407 , which can be regarded as compatible with the values indicated by others using different methods. It has been noticed that the maximum length of the etched tracks is directly proportional to alpha energy while exponentially to saturation time of the length.