Few public services impact the built environment to the extent of public transport. Our transportation options define city form, shape living patterns, underpin economic efficiency, and help realize social equity. For captive users in developing nations, public transport is oft en the only viable option for accessing jobs and public services. For developed nation cities, public transport is increasingly seen as an integral instrument in addressing traffic congestion, local air quality, energy security, and global climate change. However, delivering quality and cost effective public transport has been largely unrealized in the vast majority of the world's urban areas. Historically, a city's options for addressing public transport were defined by a limited set of technologies, each with varying degrees of cost and quality. A reasonably affordable technology that provided a quality customer experience seemed beyond the reach of transport planners. And then, a small group of innovative policy and design professionals in a relatively unknown Brazilian city reinvented the sector. Bus Rapid Transit (BRT) was created to deliver metro-like capacity and quality but at an affordable price. Within a few decades, BRT has redefined what is possible with public transport. BRT is a high-quality bus-based public transport system that uses segregated rights-of-way, rapid and frequent services, integrated routes and corridors, secure and weather-protected stations, sophisticated fare and information systems, clean vehicle technologies, ease of access for pedestrians and cyclists, and excellence in marketing and customer service. At a typical cost of US$ 3 million to US$ 10 million per kilometre constructed, BRT is within the reach of a wide range of municipal financial conditions. In other words, BRT mimics the speed, capacity, and amenity features of the world's best metro systems but at a fraction of the cost. Today, approximately 100 BRT systems are operational and a near equal number is under development. As BRT has spread across the globe, it has also become known as one of the best examples of south-to-north technology transfer with many developing-nation cities, such as Curitiba and Bogotá, providing the innovation that has reshaped public transport elsewhere including in wealthier cities. This issue of Built Environment traces both the history and the current trends with BRT across the globe, providing a regional perspective on progress and challenges.