For many people, walking should be a practical and healthy way to get around — yet it accounts for less than 3 percent of all commute trips in the United States. Even when a destination is nearby, dangerous or uncomfortable street conditions can take walking effectively off the table. To understand when walking is truly a realistic option, the Cook County (Illinois) Department of Transportation and Highways sponsored a pilot study with a University of Minnesota research team, led by Accessibility Observatory researcher and CTS scholar Shirley Shiqin Liu, to find a better way to map pedestrian networks and measure how comfort and safety affect people’s ability to reach the places they need to go.
“Right now, heavy traffic and poor street designs make walking uncomfortable or unsafe for too many residents,” Liu says. “Our goal was to create a scalable, automated tool to help communities easily spot barriers to walkability and spend infrastructure dollars where they will do the most good.”
To evaluate walking comfort effectively, the team adopted the Pedestrian Level of Traffic Stress (PLTS) framework, which scores streets on a scale from Level 1 (safe for all users, including children) to Level 4 (dangerous for most people) based on factors such as traffic speed, number of lanes, sidewalk presence, and buffer separation from vehicles. The goal was to apply this scale to a massive area like Cook County — which includes the Chicago metro area — affordably by using OpenStreetMap, a free public digital map database.
To accomplish this goal, the researchers needed to overcome a major technical hurdle: on digital maps, sidewalks and vehicle lanes are drawn as separate, unassociated lines. Although pedestrians’ actual stress levels depend heavily on the traffic flowing right next to them, the data do not naturally link the two pieces together to evaluate a safety score.
The research team solved this by writing a custom software program that acts as a digital matchmaker. The program automatically draws a boundary around roads, then finds neighboring sidewalks and links them together, even accounting for complex layouts, including multi-level bridges and tunnels. If a street is missing data such as speed limits, the software estimates the missing information based on the type of road, whether a residential street or a major highway. By successfully building this framework and creating a pedestrian stress map for Cook County, the pilot project proved that this kind of automated mapping for walking conditions across communities is possible.
Matthew Krause, senior planning specialist with Cook County’s Department of Transportation & Highways, says the PLTS pilot complements the county’s bike plan by clarifying where walking feels most stressful — insights that closely align with how the department evaluates low-stress bike facilities.
“While bicyclists and pedestrians share many needs, each group experiences the network differently. Recognizing these overlapping but distinct needs, the pilot strengthens our ability to support active transportation planning across Cook County, helping communities plan for future corridors and guide transportation investments that create a more connected, comfortable, and equitable low‑stress network,” he says. “We encourage municipalities and partners to use these findings to shape local priorities and advance safer, more accessible mobility options for all residents.”
In the future, the researchers plan to refine the tool into an open-source program that will enable other local transportation agencies to gain insights into their own pedestrian networks and evaluate whether residents can realistically reach the everyday destinations — such as grocery stores, schools, and transit stops — they depend on by walking safely and comfortably. Next steps include refining the software and expanding the analysis to answer a deeper question: not only where streets are stressful, but whether that stress is actually preventing people from getting where they need to go.
“Ultimately, this work could help local planning agencies shift from reactive to proactive planning,” Liu says. “Instead of waiting for injuries or complaints to flag a dangerous road, planners could use our tool along with free map data to understand whether street conditions are cutting people off from destinations they need and target infrastructure investments in high-priority areas for better pedestrian accessibility.”
— Megan Tsai, contributing writer
