TITLE:
Evaluation of the Impact of Presence Lighting and Digital Speed Limit Trailers on Interstate Speeds in Indiana Work Zones
AUTHORS:
Rahul Suryakant Sakhare, Jairaj C. Desai, Jijo K. Mathew, John D. McGregor, Darcy M. Bullock
KEYWORDS:
Work Zone Safety, Probe Data, Work Zone Practices, Speed Study, Construction Zone Speed Reduction
JOURNAL NAME:
Journal of Transportation Technologies,
Vol.11 No.2,
March
23,
2021
ABSTRACT: Work zone safety continues to be one of the important focus areas for
transportation agencies. Previous studies have identified that vehicle speed
and lighting conditions are significant risk factors impacting work zone
safety. This study evaluated the impact of
the use of presence lighting and digital speed limit trailers on nighttime
motorist speeds using commercially available connected vehicle speed data.
Geospatial analysis was conducted on over 500,000 connected vehicle records to
linear reference nearly 18,000 records from 195 unique trajectories to study
section during the study period of 2 days. Results showed that median speeds
reduced by 4 to 13 mph from 11PM to 7AM during the deployment of presence
lighting and speed limit trailers compared
to base conditions. A Kolmogorov-Smirnov (KS) statistical test comparing 105 vehicles traveling through the
construction zone with presence lighting and speed limit trailers with a
group of 90 vehicles during base condition indicated the speeds during the
deployment of presence lighting and speed limit trailers were lower than the
base condition. Also, increased compliance with the 55 mph speed limit was
observed when the presence lighting and digital speed limit trailers were
deployed. However, there were two hours (3AM to 5AM) where speeds increased by
0 - 4 mph, perhaps due to the
low volume at that hour. The encouraging results support the further deployment
of presence lighting and speed limit trailers in nighttime construction zones
for reducing vehicle speeds. Those future deployments should be monitored with
connected vehicle speeds to collect additional data to broaden the evaluation
of these speed mitigation techniques over a diverse set of construction zone
activities.