In this work we investigate the role of particles interactions in determining the macroscopic behaviour of a heterogeneous 1-dimensional system modeled by TASEP. We combine a theoretical approach based on cluster-mean field approximation with Kinetic Monte Carlo simulations in order to understand how the non-equilibrium steady states of the system are affected by the parameters regulating the interaction in the interesting case of repulsive particles. It turns out that on increasing the repulsion beyond a given threshold value one observes a qualitative change in the shape of the current-density relation which entails the appearance of a new phase, with stationary density profiles exhibiting more than one shock.