The Tracking Tile project is an investigation that combines a very interesting material and its application in the urban context. The translucent concrete, mostly used for esthetic purposes, is experimented in a smart city element that aims to create an intelligent, responsive and dynamic ground, acting among people, vehicles and architecture.   Mobility is one of the main issues of our time and city citizens are frequently affected by urban problems as bad traffic, accidents or lack of information, while walking, riding a bicycle or driving a car.   What if we could create an element that responds dinamically to the traffic changes, environmental or infrastructural conditions and defines boundaries for pedestrians, cyclists and drivers? Focusing on the cyclists, the Tracking Tile project consists in creating a component from translucent concrete, embedding lights in it and making it respond to changing conditions, detected by sensors and programmed by simple coding. For a case study, Barcelona was chosen as an example: as there’s a speed limit for cyclists, this became the input to be detected. The output are the different colors that signalize bicycle paths, depending if the cyclist exceeds or not the 20 km/h. Using piezoelectric sensors, arduino code and LED rings embedded in the tiles, the variables were captured and the reponses were defined. The tiles were fabricated from laser cutted acrylic moulds, filled with usual concrete and light transmissible rods. This specific application intends to make the fabrication process feasible, narrow the research and create a practical example for a smart urban element that can be applied in numerous contexts and respond to many different variables with a large range of behaviours.       Open Thesis Fabrication Program 2013 Student: Pedro Moraes Tutor: Luis Fraguada Faculty: Areti Markopoulou, Silvia Brandi, Marc Viader,  Guillem Camprodom Project developed with BREINCO