Widening the scope for bus priority with intermittent bus lanes

In the search for improved flowing conditions for buses, many cities have i ntroduced bus lanes and incorporated bus priority schemes in their traffic control systems. However, these two instruments are insufficient in themsel ves, since bus lanes are not justified with a low frequency of buses but wi thout such lanes buses frequently have to travel in congested conditions in extended parts of their routes. This paper presents the concept of Intermi ttent Bus Lane (IBL), suggests that it could be physically implemented with longitudinal traffic lights, discusses its fields or application and point s to the mathematical solution of some of the most relevant control problem s associated with it.