Exploring Traffic Speed Patterns for the Implementation of Variable Speed Limit (VSL) Signs

Abstract

Traffic congestion is a prevalent issue during peak travel hours on roads in the United States. This study focuses on identifying suitable road links in Charlotte, North Carolina, for implementing variable speed limit (VSL) signs. Real-world traffic speed data collected over one year was analyzed to identify specific road links with favorable characteristics for VSL sign installations. The analysis considered weekdays, weekends, and specific times of the day to capture variations in speed patterns. The results revealed that roads with lower speed limits consistently experienced speeds exceeding the posted speed limits, suggesting additional enforcement or safety measures. For roads with higher speed limits, mean speeds were generally close to the speed limits, but the 85th percentile speeds exceeded them, indicating a potential need for speed management measures. Road links with a 45/50 mph speed limit display a unique pattern compared to other clusters. The mean speed on these roads decreases as the standard deviation increases. The findings contribute to understanding traffic speed patterns and provide valuable insights for transportation planning and management.