Walking and cycling are essential to creating healthy, equitable, and sustainable transportation systems. Yet, roadways and paths are not all alike in how people experience comfort and safety as they travel. Level of Traffic Stress (LTS) frameworks systematically evaluate how road and intersection characteristics affect people who walk and bike.
Every street segment and crossing is scored on a scale from 1, low stress and comfortable for all users to 4, high stress and tolerable only to the most experienced. Using this scale, LTS scores reveal where street networks support comfortable travel and where critical gaps force people onto high-stress routes or prevent them from reaching essential services and destinations.
The Accessibility Observatory has developed methods to assign LTS scores to every street segment based on roadway attributes using open-source data and tools, and applies these stress-informed networks to measure destination accessibility. They measure destination accessibility by the number of jobs, schools, grocery stores, and other essential services people can potentially reach within a reasonable travel time using only comfortable, low-stress routes by walking or cycling.
The gap between what people can reach using all streets rather than low-stress routes quantifies the real cost of an incomplete walking and cycling network. The gap also highlights areas where infrastructure improvements can fill gaps and make the biggest impact. This approach supports performance measurement, project prioritization, and scenario evaluation for transportation agencies and planners.
Projects and Resources
Level of Traffic Stress and Bike Access Evaluation for Cook County, IL — This research project developed a county-wide bicycle LTS dataset and the customized BikeAccess tool for stress-informed accessibility analysis.
Pedestrian Level of Traffic Stress (PLTS) Pilot Implementation for Cook County, IL — This research project implemented the PLTS framework to score pedestrian segments and crossings county-wide and enable PLTS-informed walking accessibility calculations, featuring a custom routing engine.
Access Across America: Biking — This report, issued annually, evaluates and ranks the 50 largest U.S. metropolitan areas by bicycle accessibility to jobs using low-stress and medium-stress networks.
Transportation Research Record article, "Implementing Low-Stress Bicycle Routing in National Accessibility Evaluation." — This article examines how safe bike routes impact people’s ability to reach jobs, and shows where networks need improvement on a national scale.
CTS Webinar: Asphalt Art and Aesthetics—Research, Guidance, and Community Impacts — This webinar featured Shirley Shiqin Liu's presentation Pedestrian Level of Traffic Stress and Walking Accessibility.