State study evaluated the impact of queue warning trucks ahead of interstate work zones using 370 hours of visual alert and 16,000 hours of digital alert data.
Indiana, United States
Impacts to Traffic Behaviour From Queue Warning Truck: Current Pilot Project
Summary Information
A queue truck warning is a truck placed ahead of a work zone to alert motorists of queued traffic. This project evaluated the impact of the deployed queue truck warning program for interstate work zones in Indiana, aiming to enhance the safety and lower the risk of crash for motorists approaching work zone queues. More than 16,000 truck-hours of alerting, including both visual (queue truck warning) and digital (navigation application and in-vehicle infotainment system) alerts, was provided to motorists across various interstates in Indiana over a 26-month period, from May 2020 to July 2022. A total of 53 queue trucks were used during the study period. Additional, trajectory data extracted from granular connected vehicles (CVs), including hard braking events and traffic speeds, from May 2021 to July 2021, to evaluate the impact of queue warning trucks.
METHODOLOGY
A comparative analysis was conducted to evaluate the deployment of queue trucks in interstates of Indiana, by comparing the telematic data collected from queue warning trucks with the site manager records provided by INDOT (Indiana Department of Transportation). Analysis was conducted using hard braking events and traffic speeds from CVs. A longitudinal comparison of approximately 370 hours of queueing with queue warning trucks present and 58 hours of queueing without queue warning trucks present were evaluated in the analysis.
FINDINGS
- The presence of queue warning trucks resulted in an approximate 80 percent decrease in hard braking events, which are indicative of crash risk, suggesting that the use of queue warning trucks can lower the likelihood of crashes.
- The traffic speeds gradually decreased from approximately 1,500 to 2000 feet in advance of the location where the queue truck was deployed, indicating that the queue trucks were successfully alerting drivers and reducing traffic speeds early ahead of the work zone.
