Modelling Pedestrians for an Integrated Transport System ? Pedestrian Simulators Compared
S Ahuja, T van Vuren, Mott MacDonald, UK; M G H Bell, Imperial College, UK
Most modelling exercises and packages ignore the individual pedestrian or pedestrian journeys altogether. To carry out a holistic economic appraisal of an integrated transport system we must take into account not only private and public transport users, but also individual pedestrians. Integrated transport systems make the objectives of traffic signal control more complicated. There are trade offs involved between pedestrian safety, bus and light rail priority. They include conflicting aims to reduce delays to pedestrians and to other road (car) traffic. A true integrated solution is one that looks at the needs and problems of all different users individually and tries to find a common path to address the individual issues.
Over the last decade there has been an increase in interest in traffic microsimulation models. However, the key focus of these models has been the vehicular traffic and most often the mathematical simulation of pedestrian traffic has been ignored. One can also find an increase in interest in pedestrian simulation in literature over the last 10 years. However, most of this research has concentrated on simulation of pedestrian movement under 'stressed' evacuation conditions rather than simulation of pedestrian route choice. For example, past research has been primarily driven by applications in building evacuation.
This paper presents an audit of current pedestrian simulators and compares the theory and methodology used in their development. It presents an insight into nine different simulation programs which include PEDROUTE, PAXPORT, LEGION, SPACE SYNTAX suite, EXODUS, STEPS, PEDGO, SYMULEX and VISSIM. The study proposes a benchmarking mechanism to evaluate fitness of pedestrian simulators for applications in a transport context. The paper compares the results of applying the simulators (apart from LEGION) to a test site, highlighting the strengths and weakness of each of the simulators.
The paper also reviews past research into simulation of pedestrian movements (i.e. how they walk between spaces) and simulation of pedestrian paths (i.e. how pedestrians decide their routes between destination points). A simple pedestrian simulator has been developed for an application in VISSIM microsimulation package.
A methodology has been developed to include pedestrian movements into the appraisal of integrated transport schemes which includes modelling the interaction of pedestrians with traffic signals, public transport systems and traffic. It comprises modelling of pedestrians on both a macroscopic (area level) and microscopic (link level) scale, together with all other traffic. It includes dynamic assignment of pedestrian origin-destination movements to replicate their route choices. Finally, an economic appraisal of the integrated transport scheme is carried out using Transport User Benefit Appraisal (TUBA) software which takes into account not only vehicular time savings but also pedestrian time savings.
The study identifies areas for further research to make pedestrian simulation models more flexible by taking pedestrian route choice into account, to create a valuable policy analysis tool for the urban built environment.
Association for European Transport