We analyze the impacts of several improvements to urban transport and find that the bus can be made much more attractive by the simultaneous provision of dedicated lanes and higher service frequencies. At the same time, fare reforms, including free public transport, have limited impacts and do not seem to play an important role in reducing the use of the private car. In addition, our analysis considers active modes, bicycles in particular, and shows how they substitute for, or complement, public transport. We find that substitution prevails when public transport is rather accessible by walking (small spacing between the stations), but complementarity arises when the number of stations is small (large spacing between the stations). Our analysis is based on a micro-simulation approach, allowing us to develop a realistic and flexible framework where features like traffic lights, location of the stations, and road crossings for pedestrians are explicitly described.