Acoustic barriers are structures used to block or reduce noise propagation, improving people’s quality of life. Barriers installed to mitigate traffic noise traditionally consist of continuously installed acoustic panels. In contrast, this work proposes the development of a directional barrier consisting of discrete cylindrical elements of stepped height distributed in the form of a sonic crystal. The barrier is designed to suppress transversely especially the frequency of 1000 Hz, the frequency at which the sound peak of rolling noise occurs. In order to test the sound effect of this barrier, numerical simulations of acoustic propagation are performed using FEM/BEM. The final objective aims to develop a sound barrier for application in urban environments that fulfils a dual application: mitigating noise pollution, but allowing a certain directivity of the noise from the transit of a vehicle to act as an acoustic warning element for pedestrians.