Simulator and Field Study of Green Lights on Truck-Mounted Attenuators in Missouri during Mobile Operations

Abstract

Mobile work zones for various types of moving operations (e.g., striping, pothole patching, sweeping) are an important component in highway maintenance activities which have particular safety issues. To help mitigate the risk and severity of collisions, a truck-mounted attenuator (TMA) is attached to a construction vehicle, typically equipped with amber/white lights. Despite these visible warnings, collisions involving TMAs and traffic still occur. In an effort to improve upon the traditional amber/white lights, the use of green lights on TMAs was investigated. The study included the evaluation of four light-color configurations: amber/white, green only, green/amber, and green/white. Driving simulator tests obtained various driver behavior measures, including the first blinker distance, merge distance, work zone and arrow direction recognition distance, and disability glare. Vehicle speeds were captured in both a simulator study and a field study. In the simulator study, the use of the amber/white combination led to the highest work zone visibility but also created the greatest concern with disability glare. Although the green-only configuration led to the lowest disability glare, it also resulted in low visibility. The results showed an inverse relationship between visibility (awareness of work zone) and arrow board recognition (easy on eyes). Other findings from the field study include lower traffic speeds for the green light TMA and lower vehicle speeds for lower TMA vehicle speeds. Overall, the study showed that the four configurations had various tradeoffs and none stood out as clearly superior in terms of the performance measures.

A Simulation Study of Passing Drivers' Responses to the Automated Truck-Mounted Attenuator System in Road Maintenance

“…Driving simulators have been widely adopted in research studies, such as driver behavior study, vehicle design, and road design [14,35,8]. While no simulator has been developed and widely used for the ATMA system, some simulators were created for TMA studies [2,27,38]. These studies were mainly focused on evaluating TMA markings and warning signs by designing optional alternatives to TMA in the simulator.…”

“…One scenario uses a human flagger, and the other uses an automated flagger assistance device on a TMA. Zhang et al [38] in the same research team used the same simulator to evaluate four light-color configurations (i.e., amber/white, green only, green/amber, and green/white) on TMAs to improve upon the traditional amber/white lights.…”

“…According to specifications of a research topic, simulated driving scenarios are created. Some driving simulators have been designed for TMA studies [2,27,38], but not for the ATMA yet.…”

Comparison of Three Traffic Management Plans Showing Shadow and Police Vehicle Effects on Driver Behavior at Highway Single Lane Closures

“…However, while arrow recognition was higher for green lighting, visibility was lower compared with amber/white lights. It was noted that such an inverse relationship had been previously observed in research by Gibbons (14), resulting in the need to consider "tradeoffs" in relation to visibility, glare, and recognition (13).…”

“…With lighting critical to work zone visibility, Zhang et al. ( 13 ) conducted field and simulator testing of different configurations for TMA-mounted arrowboard lights, including a trial of green lights as well as commonly used amber and white lights. In the results of the study, green lighting appeared to result in lower overall speeds of vehicles passing a TMA.…”