When Kyu Ri Kim was seven years old, she was struck by a car while walking in her neighborhood where there was no separate walkway for pedestrians in Seoul, South Korea.

Kim, who is now an adjunct research associate at Portland State University (PSU), received nerve damage in her legs and had to use a wheelchair for several days after the incident. This experience launched her interest in pedestrian safety, which eventually led to her 2024 doctoral dissertation research project: "The Central Role of Perceived Safety in Connecting Crash Risk Factors and Walking Behavior."

"That was the real starting point, my personal experience. And I'm curious whether other people really do understand the real risk around them. What are the crash risk factors around them and how are they different from individual perceived risk?" Kim said.

Her dissertation, supported by funding from the National Institute for Transportation and Communities (NITC), illuminates the relationship between pedestrian crash risk factors and perceived safety, as well as the relationship between safety attitudes and walking behavior. How the interplay between these factors influences people's behavior needs to be better understood in order to improve pedestrian safety and the walking environment.

“There are so many papers explaining the reasons for crashes, especially pedestrian crashes. But I wanted to explore what's going on in people's minds. I mean what they think, how they feel, and what they actually recognize around them about their risk while they're walking. Those perceptions and attitudes definitely affect their daily behavior," Kim said.

DATA COLLECTION AND ANALYSIS

Kim's dissertation used data from three primary sources: 

1. An original survey of 551 residents in 10 neighborhoods in Oregon conducted in 2023; 
2. Pedestrian crash data that occurred in Oregon for 2018–2022; 
3. Pedestrian count data collected at 65 sites in 2022. 

These were complemented with built environment data. Over a five year period, 729 pedestrian crashes occurred in the census block groups surrounding the 65 sites.

One result shows that pedestrian volume measured as pedestrian count data has better predictive power to explain pedestrian crashes than pedestrian volume measured as population density. Even with only two days of count data available, the counts were still more accurate than population density in terms of predicting crashes. This result supports the need to collect pedestrian volume data in various places to develop road safety plans and policies.

Kim also tested whether crash risk factors predict actual pedestrian crashes in the study areas. In addition to pedestrian volume, crash risk factors in macro-level areas—including mixed-use land areas, commercial land areas, and public transit stops—were found to be significant in predicting pedestrian crashes.

KEY FINDINGS

Overall, pedestrians' attitudes were mainly determined by their subjective experiences in a given environment, rather than their actual crash risk.

For example, after controlling for other risk factors (including speed and traffic volumes), pedestrians felt more threatened in areas with more intersections and mixed land use. 

However, intersection density is not significantly related to the number or severity of pedestrian crashes. This may be because vehicle speeds decrease as the density of intersections increases. This implies that when pedestrians encounter intersections more frequently, they perceive more threat, even though the environment is not significantly riskier.

"People's perceptions of those risks around them may affect their attitudes, and finally affect their mode choice," Kim said.

In terms of travel behavior, positive safety attitudes and nearby sidewalks increase walking frequency. On the other hand, large commercial areas, faster vehicle speeds, and more vehicles in their households significantly reduce people's walking frequency. 

One likely reason for the negative relationships with having commercial areas nearby is that most survey respondents were walking primarily for exercise, to walk their pets, or for entertainment rather than to visit specific destinations such as work, school, or restaurants.

"I initially thought commercial areas or parks would encourage people to walk more. But actually, they need safe sidewalks in their neighborhoods. This may suggest that pedestrian facilities or infrastructure for connectivity and accessibility may be more helpful in encouraging people to walk rather than interesting and fun destinations themselves," Kim said.

After receiving her PhD in Urban Studies and Planning from PSU in 2024, Kim started work as an adjunct research associate for TREC, working on multiple projects related to active transportation and the safety of vulnerable road users.

Photo by zenstock/iStock

Portland State University's Transportation Research and Education Center (TREC) is home to the U.S. DOT funded National Institute for Transportation and Communities (NITC), the Initiative for Bicycle and Pedestrian Innovation (IBPI), PORTAL, BikePed Portal and other transportation grants and programs. We produce impactful research and tools for transportation decision makers, expand the diversity and capacity of the workforce, and engage students and professionals through education and participation in research. To get updates about what's going on at TREC, sign up for our monthly newsletter or follow us at the links below.

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