In most of the densely populated urban areas, many pedestrians may walk directly to the transit stations but some pedestrians may well carry out discretionary shopping activities. They may go into the stores nearby and shop for several minutes or even spend an hour in the shops. If the shopping activities are not explicitly considered in the modeling of the pedestrian movements, the spatial distribution of the area and the temporal distribution of the pedestrians could be questioned. Thus, the duration of shopping activities is of prime importance that affects the pedestrian flows on streets by times of the day.;This research puts forward an activity-based approach to model and simulate the pedestrian travel and activity choice behaviors in a congested urban shopping area with empirical data collected for calibration and comparison. The pedestrian activity behaviors are explicitly taken into account in the newly developed Pedestrian Activity-Simulation (PAS) model which can be used for assessing the service performance of the pedestrian facilities. Traditionally, the pedestrian trip-based simulation model does not consider the activity behaviors. It is assumed that pedestrians walk from origin to destination purely without any activities performed on the way. The results from the model may be questioned if the traditional trip-based simulation model is adopted for simulating the pedestrian movements in a congested urban area without particular emphasis on the pedestrian activity behaviors. This research does not only focus on the pedestrian movements, but involves a broad view of walking behaviors, such as the pedestrian activity and destination choices, how the bi-directional pedestrian flow affects walking speeds, the walking speed variations and the Level-of-Service (LOS) standards of the pedestrian facilities.;The newly developed PAS model consists of four necessary elements. They are: (i) the pedestrian activity and destination choice models, (ii) the generalized walking functions for signalized crosswalks and outdoor walkways, (iii) the walking speed variations with the uni-directional and bi-directional pedestrian flow effects and (iv) the time sliced pedestrian demands in terms of origin-destination matrices. The newly proposed PAS model is calibrated and compared with empirical data. A case study in a Hong Kong urban area has been carried out to assess the performance of the PAS model and the traditional trip-based simulation model.;In order to collect data for model calibration and comparison, a large-scale survey was conducted with the assistance of 70 surveyors on a typical Friday 5 August 05. Two survey periods were chosen, i.e. an off-peak period from 2 p.m. to 4 p.m. (without Pedestrian Scheme) and a peak period from 5 p.m. to 7 p.m. (with Pedestrian Scheme). Two types of surveys were conducted simultaneously: (a) an observational survey; and (b) a tracking survey. Data collected from the observational survey have been used to examine the generalized walking speed functions, walking speed variations and pedestrian demand in terms of origin-destination matrices. In addition, data would be generated from the tracking survey to calibrate the pedestrian activity and destination choice models.;An independent set of observed data is collected from the observational and tracking surveys so as to compare the simulation results. Comparisons are made between the observed data and the results simulated by the newly proposed PAS model. In addition, the performance of the newly developed PAS model and the traditional trip-based simulation model are examined. Comparison results highlight the limitations of using the traditional trip-based simulation model to simulate the pedestrian flows and the total journey time particularly when the pedestrian shopping activities are concentrated in a congested urban area. This feature confirms that the pedestrian activity behaviors are of prime importance when pedestrian movements in the densely populated urban areas are considered.;In connection to the above, the generalized walking time function for signalized crosswalks and the walking speed variation function are proposed and calibrated with the empirical data which take into account the bi-directional pedestrian flow effects. It is shown that different designs, depending on walking speeds for signalized crosswalks, are required as different bi-directional pedestrian flow effects would have significant impacts on determining the duration of the pedestrian green time at signalized crosswalks particularly in the congested urban areas with high pedestrian flows. Similar calibration of the generalized walking speed function is carried out for outdoor walkways. Finally, a new set of pedestrian LOS standards for signalized crosswalks is developed by using the data collected from the stated preference survey which is based on the perception of the respondents on the LOS boundaries which are derived explicitly for the different levels of the bi-directional flows regarding the area occupancy, pedestrian flow and walking speed at the signalized crosswalks. These newly developed LOS standards would be better able to assess the service performance of the signalized crosswalks as the bi-directional pedestrian flow effects are explicitly taken into account.
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