Macroscopic Fundamental Diagram for Urban Streets and Mixed Traffic

In the past decade many papers focused on describing the vehicular traffic stream of an arterial on an aggregate level. Unfortunately, in this considerable body of research, only a few papers account for bus systems. This paper tries to fill that gap by investigating two potential methods for estimating macroscopic fundamental diagrams of multimodal transport systems of a signalized arterial. The first approach models the motion of buses endogenously by extending the existing estimation method with the moving bottleneck theory; the second approach proposes to incorporate the effects of buses exogenously. The estimated macroscopic fundamental diagrams were then cross compared with results provided by microsimulation software that finely reproduced the traffic stream. Mean speeds of vehicles and buses produced by the different methods were similar and consistent. Finally, results of the three methods were expressed for levels of service and compared with the levels of service of the Highway Capacity Manual 2010.