The objective of this research is to develop a method to estimate pedestrian demand – or pedestrian volumes on a network – using readily available data at the sub-metropolitan scale. A more detailed presentation of the model can be found in the Pedestrian Demand Model and Crash Analysis Protocol and the Pedestrian Demand Model for Evaluating Pedestrian Risk Exposure Summary Report. In this study, we develop a pedestrian demand model that builds upon the traditional four-stage urban transportation modeling process, used extensively in regional travel demand models. But unlike regional travel models, this model functions at the pedestrian scale (at the neighborhood and street block level), utilizes readily available archived data, and operates entirely within a geographic information systems (GIS) framework.
The model has three components: trip generation, trip distribution and network assignment. Trip generation estimates the numbers of pedestrian trips that originate and end at each street block. Trip distribution connects these trip origins and destinations to estimate pedestrian flows. Finally network assignment predicts routes that pedestrians are likely to take on their journey. The end result is an estimate of the numbers of pedestrians, or pedestrian volumes, which will occur on sidewalks and intersections in the study area over a 24-hr period.
Use of the model requires the following:
- A geographic information system (GIS) and experience using it
- A personal computer
- Access to geo-referenced parcel level land use data
- A recent road centerline file (e.g. Census Tiger File)
- The traffic assignment program module – (see below)
- Aerial photos, maps or some other visual source of information of the study area
- The Pedestrian Demand Model Protocol (see below)
The model can be used for planning purposes – to forecast how many people will walk under different land use and pedestrian network configurations. For example, planners can test the impact of new development or infill development to see how many pedestrians will be walking in the area in the future. Changes to the pedestrian network, such as adding sidewalks, improving connectivity, or removing access, can be evaluated for their impacts. Model results can also be a useful tool to analyze pedestrian safety. The model output at the intersection level can be combined with pedestrian-vehicular crash data for calculation of pedestrian risk exposure (crashes per pedestrian). Intersections can be ranked by their risk exposure measure to guide planners in safety improvements and investments.
Because the model runs on a GIS platform, most local planners have the capacity to run the model themselves. This tool will bring a new resource to the issue of pedestrian planning and safety analysis and will assist public agencies in prioritizing and directing investments to mitigate problems. More information and documentation about this model can be obtained from Kelly J. Clifton (email@example.com; 503/725-2971) at the Department of Civil and Environmental Engineering at Portland State University. The development and testing of this model was made possible by a grant from the Maryland State Highway Administration, Office of Traffic and Safety, Maryland Department of Transportation.
Summary and Manual
Trip Assignment Program
Clifton, KJ; Burnier, CV; Huang, S.; Kang, MW, and Schneider, R. 2008. A Meso-Scale Model Of Pedestrian Demand, paper presented at the 4th Joint Meeting of the Association of Collegiate Schools of Planning and the Association of European Schools of Planning, Chicago, IL, July 6-11, 2008. (pdf, 2k)