The implementation of Drive-by-Wire systems is increasing due to their advantages. One of these advantages is the capability to be autonomous or semiautonomous. This paper investigates the collisions avoidance in a Steer-by-Wire and Differential Drive experimental vehicle. The Steer-by-Wire system is tested using the Ackerman formulation. Ackerman equations are modified in order to vary the vehicle’s steering ratio in function of the vehicle’s speed. As a result, better high speed vehicle’s control is achieved. The collision avoidance system works using infrared sensors around the vehicle, avoiding frontal and lateral collision. The distance to the obstacles is the parameter selected to avoid collisions (leaving the time for other actions like warnings to the driver). The fusion of the Autonomous Steer-by-Wire and the collisions avoidance system develops a semi-autonomous vehicle. This vehicle avoids collisions automatically, even if the driver does not avoid the collisions by himself, greatly reducing the probability of accidents.