Bus Rapid Transit (BRT) is growing in popularity throughout the world. The reasons for this phenomenon include its passenger and developer attractiveness, its high performance and quality, and its ability to be built quickly, incrementally, and economically. BRT also provides sufficient transport capacity to meet demands in many corridors, even in the largest metropolitan regions. In the United States, the development of BRT projects has been spurred by the Federal Transit Administration’s (FTA) BRT initiative. These projects have been undertaken, in part, because of the imbalance between the demand for “New Starts” funds and available resources. Decisions to make BRT investments should be the result of a planning process that stresses problem solving, addressing needs, and the objective examination of a full range of potential solutions, of which BRT is only one. Good planning practice means matching potential market characteristics with available rights-of-way. BRT involves an integrated system of facilities, services, amenities, operations, and Intelligent Transportation Systems (ITS) improvements that are designed to improve performance, attractiveness to passengers, image, and identity. Because they can be steered as well as guided, BRT vehicles can operate in a wide range of environments without forcing transfers or requiring expensive running way construction over the entire range of their operation. Through this flexibility, BRT can provide one-seat, high-quality transit performance over a geographic range beyond that of dedicated guideways. To the maximum extent practical, the system should transfer the service attributes of rail transit to BRT. Even where implementation of a comprehensive, integrated BRT system is not possible, many of its components can be adapted for use in conventional bus systems with attendant benefits in speed, reliability, and transit image/attractiveness. In summary, BRT is growing in popularity because it can be cost-effective and it works. This article describes BRT concepts and components, traces BRT’s evolution, gives its current status, and outlines some of the findings to date of the Transportation Research Board’s (TRB) Transit Cooperative Research Program (TCRP) A-23 project, “Implementation Guidelines for Bus Rapid Transit.”