The concept of Intermittent Bus Lane (IBL) is an innovative approach to achieve bus priority, consisting of a lane whose status changes according to the presence or not of a bus in its spatial domain - when a bus approaches such a section, the lane changes to a BUS lane, and after the bus moves out of the section it becomes a normal lane again, open to general traffic. The aim is to obtain bus priority when bus services are not so frequent, while not affecting general traffic. The IBL was developed, simulated, tested and validated in Lisbon in a cooperation between Instituto Superior Técnico, CARRIS andCâmara Municipal de Lisboa. It's main conclusions were presented at the 86th Transportation Research Board Annual Meeting, in 2007. 2006 © José Manuel Viegas, Baichuan Lu, João Vieira and Ricardo Almeida Roque