The effect of mixture lengths of vehicles on the asymmetric exclusion model is studied using numerical simulations for both open and periodic boundaries in parallel dynamics. The vehicles are filed from their length, the small cars Type 1 occupy one cell whereas the big ones Type 2 takes two. In the case of open boundaries two varieties of models are presented. The former model corresponds to a chain with two entries where densities are calculated as a function of the injecting rates α₁ and α₂ of vehicles type 1 and type 2 respectively, and the phase diagram (α₁ , α₂ ) is presented for a fixed value of the extracting rate β. In this case the first order transition from low to high density phases occurs at α₁ +α₂ =β and disappears for α₂ >β. The latter model correspond to a chain with one entry, where α is the injecting rate of vehicles independently of their nature. Type1 and type2 are injected with α₁ and α₂ respectively, where α₂ =nα, n is the concentration of type2 and α₂ ≤α₁ ≤α. Densities are calculated as a function of the injecting rates α, and the phase diagrams (α,β) are established for different values of n. In this case the gap which is a characteristic of the first order transition vanishes with increasing α for n ≠ 0.However, the first order transition between high and low densities exhibit an end point above which the global density undergoes a continuous passage. The end point coordinate depends strongly on the value of n. In the periodic boundaries case, the presence of vehicles type2 in the chain leads to a modification in the fundamental phase diagram (current, density). Indeed, the maximal current value decreases with increasing the concentration of vehicles type 2, and occurs at higher values of the global density in contrast with what was found by Schadschneider et al. [20].