TITLE:
Using Anonymous Connected Vehicle Data to Evaluate Impact of Speed Feedback Displays, Speed Limit Signs and Roadway Features on Interstate Work Zones Speeds
AUTHORS:
Jijo K. Mathew, Jairaj Desai, Howell Li, Darcy M. Bullock
KEYWORDS:
Connected Vehicle, Trajectory Data, Speed Limit, Compliance, Work Zones, Construction
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.11 No.4,
September
2,
2021
ABSTRACT: Annually, there are over 120,000 crashes in work
zones in the United States. High speeds in construction zones are a
well-documented risk factor that increases the frequency and severity of crashes. This study used connected vehicle data
to evaluate the spatial and temporal impact that regulatory signs, speed
feedback displays, and construction site geometry had on vehicle speed. Over
27,000 unique trips over 2 weeks on a 15-mile interstate construction work zone
near Lebanon, IN were analyzed. Spatial analysis over a 0.2-mi segment before
and after the posted speed limit signs showed that the regulatory signs had no
statistical impact on reducing speeds. A before/after analysis was also
conducted to study the impact of radar-based speed feedback that displays the motorists’ speed on a sign below a regulatory speed limit sign. Results showed a
maximum drop in median speeds of approximately 5 mph. Speeds greater than 15
mph above the speed limit dropped by 10% - 15%. The reduction in speeds began approximately 1000 feet ahead of the
sign and results were found to be statistically significant. The analysis also revealed that larger speed drops inside the work zone were
due to geometric constraints that required additional driver workloads,
especially during shoulder width changes and lane shifts. The results from this
study will be helpful for agencies to understand driver behavior in the work
zones and to identify proper speed limit compliance techniques that
significantly reduce driver speeds in and around work zones.