The thesis project is an exploration of interaction design possibilities within the spaces of public transport in urban India and the challenges for design in these large, disorderly contexts. These public transit spaces offer a microcosmic view of the current urban environment of India, where new paradigms of technology adoption are emerging, and provide significant scope for interaction design to learn from and contribute to in diverse ways. As the theme of public transport and its encompassing spaces are traditionally approached from urban planning and engineering perspectives, this thesis aims to explore the urbanism of transit places from the framework of place-specific computing, which is a perspective on mobile and ubiquitous computing, and a design methodology that is grounded in and emanating from the social and cultural practices of a particular place. To understand and evaluate the environment, the project makes use of elements of participatory design, brainstorming techniques like placestorming, and experience prototyping methodologies, a way for users to interact directly with the prototype, and thus at each stage of the design process explores the role of prototyping to generate reflective discussion. The thesis proposes Crowd Compass, an information service based on crowd density, that is available freely anywhere but only of value in a certain context to support a specific decision, and expires instantly. The thesis also presents a new paradigm for design in large scale, disorderly contexts: crowd density, a parameter of contextual information for transit; and the concepts of a semi-controlled space for early prototyping, analytic and generative maps for effective analysis, and the significance of design from “the inside”.