## 1 Introduction
Both systems operate in segregated paths, and while LRT bear a resemblance to trans, the BRT is essentially characterized by using public transportation vehicles on tires (buses). Furthermore, both systems require a strong support from Intelligent Transportation System (ITS) elements, this aspect being more critical to BRT, which, in the end, has the intrinsic possibility of reaching the state of a truly autonomous system. The Institute of Transportation & Development Policy (ITDP) [11] defines BRT as \"a high-quality bus-based transit system that delivers fast, comfortable and cost-effective urban mobility through the provision of segregated right-of-way infrastructure, rapid and frequent operations, and excellence in marketing and customer service\". The BRT goal is to combine the capacity and speed of a metro with the flexibility, lower cost and simplicity of a bus system. BRT systems come in many shapes and forms. However, they all aim, to varying degrees, to mimic the high-capacity, high-performance characteristics of urban rail at a much lower price [12]. According to one study, this reduction can be as much as 4-20-times less than Light Rail Transit (LRT) and 10-100-times less than metro rail systems [13]. BRT uses buses on a wide variety of right-of-ways, including mixed traffic, dedicated lanes on surface streets and busways separated from traffic. In fact, BRT has a greater potential for innovation, and it could be considered as the evolution of present collective transportation systems. Moreover, the added value provided by the latest advances in control, artificial perception and Information and Communication Technologies (ICT) might facilitate the development of new concepts enabling the creation in the near future of more flexible, fast, reliable, economic and efficient BRT systems of wider and safer use in populated areas [14]. In this regard, an interesting analysis has been released [10] reporting the full picture of the successful dissemination of BRT systems in several Latin America cities, providing the additional encouraging side-effect of environmental conditions' enhancement. Some BRT systems incorporated guidance (mechanical, optical and magnetic) to increase speed in narrow corridors, which also implies better safety and the possibility of precision docking [9], and this is why BRT could be considered as an intermediate step from classical urban transport (conventional bus services) to fully-autonomous systems [8]. Within this context, the relevance of autonomous guidance in urban transportation targeting improvement of ITS efficiency has been recognized by several authors [8; 15]. The advancement of ITS technology takes advantage of previous and parallel research on Autonomous Guided Vehicles (AGVs) and mobile robots [16]. A theoretical contribution to the automatic steering of a city bus was presented in [17], where two different approaches, linear and nonlinear controllers, were compared. The works related to the kinematic and dynamic models of wheeled mobile robots [18] have been important to understand modelling and therefore to set up the grounds for motion planning and control. For example, in [19], the implementation of intelligent and stable fuzzy Proportional Derivative-Proportional Integral (PD-PI) controllers for steering and speed control of an AGV consisting of an electrically-powered golf car suitably modified for autonomous navigation and control was reported. In [20] active steering under model predictive control was researched. In [21], a small electric mini-bus was used to demonstrate the autonomous driving capability and obstacle avoidance using GPS for localization and LIDAR for environment recognition. Lateral vehicle control [22] is one major issue that has been studied because of its relevance [23], both for warning about lateral vehicle displacement and possible automated intervening in manual driving [24], as well as for full automation, as was shown in the California PATH program [25] and more recently in the DARPA Urban Challenge 2007.