*3.2. Data Collection*

To test the effects of two design types in terms of their objective (observed) and subjective (stated) pedestrian safety, we analyzed video recordings made before and after implementation and conducted a cross-sectional questionnaire survey. The research data were collected by AURI (specifically, this paper's corresponding author collected the data as head of the Pedestrian Environment Research Center, AURI). The videos were recorded at every node and straight-link (between nodes) where the cameras could be installed in September 2014 (before) and June 2015 (after). We finally chose the nine spots on each of the nine streets, which have the straight segmen<sup>t</sup> and representative paving designs. The recordings occurred on weekdays when the weather and temperature were similar across days. Camera installation was pre-approved by the district office. The cameras were installed above eye-level to accurately capture all of the street users' activities and record the patterns in the pavement. The sites were continuously recorded from 06:00 to 21:00, and the recorded data, during the three 15-min peak periods, were extracted for analysis: morning (08:30 to 08:45), afternoon (16:30 to 16:45), and evening (19:30 to 19:45). Using this data, vehicle speed was measured as a proxy of objective pedestrian safety. The speed of each vehicle was manually calculated by dividing the distance of the pre-designated section in each street by the time it takes for the vehicle to pass in the videos.

The questionnaire survey was administered once, approximately a year after the 2014 PPS projects were completed (30th September 2015—07th October 2015). Only the residents (70%) or business owners/employees (30%) who had lived or worked near the sites for at least two years were eligible to participate in the survey. The number of respondents per site was between 100 and 106, and the total sample size was 819 people. Because the questionnaire items were about the entire streets, rather than specific locations on the streets, Sanggye-ro 3-gil and 5-gil in Nowon-gu were treated as one location for the survey (but not for the video data). The questionnaire items mainly focused on changes in peoples' perceptions of traffic safety. Although the survey data on subjective pedestrian safety merely provided descriptive data, its function was important to the interpretation of the regression results on vehicle speed.
