A Bi-Modal Microsimulation Tool for the Assessment of Pedestrian Delays and Traffic Management

There is now increasing emphasis on managing the urban transport for the benefit of all road users, particularly on the promotion of walking and cycling as more environmentally friendly modes of transport. Dynamic traffic signal controls in respond to pedestrian demand have been developed which give the flexibility and control to the network controllers to manage pedestrian and vehicle interactions and to provide priorities to pedestrians at signalized intersections. This paper describe the development made to adapt a traffic microsimulation model to include simulation of individual pedestrian movements and their interactions with vehicular traffic in a network of highways and pedestrian walkways. The pedestrian facility is modeled as a network of walkway sections and their connections. The average pedestrian flows along specific paths are predetermined and inputs to the model; pedestrians move along pedestrian walkways following these fixed routes. Each pedestrian is represented as an individual object, interacting with other pedestrians and with vehicular traffic. Pedestrian crossing behaviour is characterized in two broad categories: the " law-obeying " ones who only cross the road when the green man is on, and " opportunistic " pedestrians who may cross the road during red pedestrian signal if appropriate gaps are available. The patience of the opportunistic-type pedestrians is also represented. A number of pedestrian actuated signal policies are implemented. Pedestrian stage length may vary with the number of waiting pedestrians. A pedestrian stage may be extended for late crossing, or vice verse, be terminated early if all pedestrians have crossed the road. Similarly a pedestrian stage may be brought forward in excess demand, or vice verse, be cancelled in absence of pedestrian demand. A vehicle actuated signal policy is also represented where a vehicle green stage may be extended at the detection of approaching vehicles. Interactions between vehicle-actuated and pedestrian-actuated signal policies are dealt with in the model. An example of the model application to a signalized intersection with pedestrian and vehicle actuated signal controls is presented. The results show that the model response logically to input parameters and that the model framework provides a viable technique for traffic analysis and traffic management. Traditionally urban network management is geared towards minimizing delays to vehicles. When a pedestrian phase or stage is provided at a signalized junction, the guideline from the UK Department of Transport has been that whilst providing safety to the pedestrian, there should be minimum delay to traffic (DOT 1981). …