Whilst debate comparing the technologies of bus-based transit ways with rail systems continues, the comparative cost advantages and capability of responding to rapidly changing mobility needs offered by Bus Rapid Transit (BRT) systems are well acknowledged. Istanbul has recently developed its 42 km BRT network with further extensions currently being constructed. The Istanbul BRT system (Metrobus) consists of three main sections. The first section (2007) was initially built on the European side of the city through a high demand arterial and its extension as the section was completed in 2008. It received criticism for having been preferred over rail alternatives. The third section (2009) runs over one of the two Istanbul Strait (Bosporus Strait) Bridges connecting Asia and Europe, by which Metrobus has uniquely acquired the distinction of crossing a major water barrier and connecting two continents. Istanbul Strait is a major transportation bottleneck and source of congestion and Metrobus is the only transit system for crossings. Shortly after the opening of the bridge section, the whole system has recorded a directional capacity of 24,000 passengers/h and patronage of 620,000 daily ridership. The number of passengers attracted from car users and intermediate forms of public transportation is also notable. This paper first contributes to the BRT literature by introducing this special and recent BRT system with all its planning and operational aspects. Furthermore, for policy guidance, Metrobus is evaluated as to whether it has made effective inputs for sustainable development and mobility aims in Istanbul. (C) 2012 Elsevier Ltd. All rights reserved.