Buses and coaches are massive Passenger Transportation Systems (PTS), because they represent more than half of land PTS in the European Union. Despite that, bus accident figures are lower than other means of transport, but its size and weight increase the severity of accidents in which buses are involved, even at low speed. In urban scenarios, turnings and maneuvers around bus stops are the main causes of accidents, mostly due to low visibility, blind spots, or driver's distractions. Therefore, there is an increasing interest in developing driving assistance systems to avoid these situations, among others. However, even though there are some solutions on the market, they are not meant to work in urban areas at low speed and with the sole purpose of preventing collisions with pedestrians. In this sense, the paper proposes an active safety system for buses in maneuvers at low speed. The safety system consists of haptic feedback devices together with collision avoidance and risk evaluation systems based on detected people nearby the bus. The performance of the active safety system has been validated in a simulated urban scenario. Our results show that driver's reaction time is reduced and time to collision increased due to the proposed low-speed active safety system. In particular, it is shown that there is a reduction in the number of high risk cases and collisions, which implies a considerable improvement in safety terms. In addition to this, a brief discussion about current regulations for innovative safety systems on real vehicles is carried out.