A work zone is identified as “that part of the highway being used or occupied for the conduct of highway work, within which workers, vehicles, machinery, materials, supplies, excavations, or other obstructions are present,” according to the US Department of Transportation Federal Highway Administration (FHWA). This means that construction workers are exposed to live traffic as well as heavy equipment in their work zone. During peak construction season, approximately 20% of the nation’s highway system is under construction, with over 3,000 work zones, as per OSHA. And according to CPWR, 1,166 fatalities occurred in work zones between 2003 and 2015. Furthermore, despite the fact that researchers, practitioners, and regulatory agencies have implemented a number of strategies to combat this threat, it continues to exist. Between 2011 and 2015, road construction sites were responsible for 70% of all fatalities in the construction industry. As a result, researchers decided to investigate the use of technology to prevent or reduce workplace accidents. The researchers developed and continue to develop technologies that aid in improving work zone safety, which the FHWA refers to as “smart work zone systems.”
A “smart work zone system” is the application of computers, communications, and sensor technology to highway transportation and possesses the properties of being automated, reliable, in real-time, and portable. In the following section, we’ll go over a few of these technologies:
1. The Autonomous Truck Mounted Attenuator
Contractors and maintenance agencies used to use the Truck Mounted Attenuator (TMA) truck as a crash barrier truck, parked at the tail end of the construction zone to protect workers in a work zone. The driver of this TMA truck, on the other hand, is sitting in the truck, waiting to be struck by another vehicle and thus suffer the consequences of the collision. Furthermore, the Federal Highway Administration (FHWA) reported that approximately 70 crash-related injuries and 12 fatalities occur in work zones every week in the United States. As a result, the job of a TMA truck driver is extremely hazardous.
In 2016, Royal Truck & Equipment teamed up with KRATOS Unmanned Systems Division to develop ATMA trucks, which put the TMA truck driver out of harm’s way in the event of an auto accident. The ATMA truck is a self-driving vehicle that follows the vehicle in front of it. It combines military technology (in the form of a follow-the-leader truck) with the TMA truck. Because the unmanned and manned vehicles are electronically linked, the manned leading vehicle has a module on the roof that sends GPS data (with +/- 4-inch accuracy) (ecrumbs), which is picked up by the following driverless vehicle and matches the leading vehicle’s position, direction, and speed.
2. Drivers’ Smart Assistance System
A Drivers’ Smart Assistance System (DSAS) is a technology that facilitates communication between infrastructure and vehicles and provides motorists approaching a work zone with appropriate visual and verbal warning messages. These early warning messages give drivers enough time to adjust their driving style and react safely to the temporary change on the highway (work zone), improving workplace safety. DSAS is based on the application of Radio Frequency Identification (RFID) tags with unique identification numbers on each piece that is installed on the roadside in front of the relevant traffic signs, according to Qiao Fengxiang of Texas Southern University. The RFID readers, on the other hand, are installed in the vehicles. The RFID reader receives signals from the tags on the traffic signs as the driver approaches the work zone, and the system translates the tag ID into a pre-programmed message, such as “Construction Work Ahead,” “Right Lane Closed,” or “Speed Limit 25 mph.” The vehicle’s computer system checks for tag and GPS information receipt. If a search of the tag inventory database reveals that the tag ID is valid, the motorist receives appropriate visual and audible warning messages. As the driver approaches the work zone, the verbal and visual warning information encourages them to slow down, stay alert, and drive through it. Surprisingly, this safety technology serves two purposes: it reduces air pollution around the work zone (as the driver slows down) and it improves worker safety within and around the work zone.
3. Work Zone Intrusion Technologies
Work Zone Intrusion Technologies are devices that use one or more sensors mounted on standard work zone barriers to detect intrusion. A high-pitched alarm would be activated and sounded by the base station near the workers when an errant vehicle came within range of a sensor, warning the workers that their protective work zone had been violated. This system assumes that an errant vehicle has knocked over the hardware and entered the work zone. The concept of such systems, according to Ibukun Awolusi of the University of Texas, is that the alarm mechanism would warn workers so that they would have enough reaction time to move away from the hazardous location. A detection unit and a receiving unit are included in some intrusion alarm systems; the receiving unit is activated when the detection unit is triggered or activated. Because of the alarm’s loudness, it may also alert a distracted or drowsy motorist as they approach the work zone, allowing them to avoid the work zone or decelerate before reaching workers or their equipment.
4. Hybrid Work Zone Information System
Congestion in work zones can quickly worsen and create dangerous conditions, especially during rush hour. Dedicated short-range communication (DSRC) is a traffic management technology that uses vehicle-to-infrastructure and vehicle-to-vehicle communication to read travel safety parameters like traffic congestion point, length of congestion, and travel time (TT). This information is sent to DSRC-equipped vehicles so that the driver is aware of the situation as they travel down the road. As a result, Ibrahim of the University of Minnesota combines DSRC and PCMS technology to create a Hybrid Traffic Information System (HTIS) for vehicles without DSRC at the early stages of DSRC deployment, allowing them to benefit from the technology’s potential. This HTIS combined DSRC’s ability to acquire traffic data with the dynamic display property of the Portable Changeable Message Signs (PCMS) for use in work zones to improve traffic mobility, worker safety, and motorist safety. In the work zone, the PCMS has been used extensively for traffic control and to display critical travel-related information. The PCMS in the HTIS is located in a highly visible location where road users (motorists, cyclists, pedestrians, etc.) can easily see it, and it obtains the traffic information it displays from nearby vehicles equipped with DSRC technology. The technology has been shown to improve work zone safety by giving the driver more time to react safely to changes on the road; however, drivers of vehicles without DSRC are excluded from taking advantage of this safety feature.
5. Wireless Technologies for Personnel and Equipment Proximity Sensing in Work Zones
There is a lack of understanding about how workplace safety technologies provide construction workers and equipment operators with an extra layer of hazard awareness. During hazardous proximity situations in work zones, this type of technology provides real-time alerts to equipment operators and pedestrian workers. Using Bluetooth technology, Georgia Institute of Technology’s JeeWoong Park developed a proximity detection and alert system. Three components of the developed system – the equipment protection unit, the equipment operator’s Personal Protection Unit (PPU), and the pedestrian worker’s PPU – communicate in real time and provide alerts to construction workers and equipment operators in roadway work zones during hazardous proximity situations. Before the system can be used in the field, the components of this technology must be calibrated and mounted. The Bluetooth PPU is easily accessed through an application that can be downloaded on any smart device, such as an iPhone or iPad, and this smart device can be carried in the worker’s pocket or attached to the belt.
Three different alert distances are possible with the system. Depending on the location of the pedestrian worker inside the precalibrated hazardous proximity zone, the alert distances allow for variations in audible alerts and vibrations. The audible alert intensifies in frequency of beeps and vibrations to the pedestrian workers’ and equipment operators’ PPUs as the ground worker approaches the piece of construction equipment and penetrates closer to the Equipment Protection Unit. These alert distances could be adjusted based on the type of construction equipment and the conditions on the job site.
The developed Bluetooth proximity sensing system required the least amount of infrastructure and calibration time when compared to RFID and magnetic field proximity detection and alert systems. Above all, the Bluetooth proximity detection and alert system can provide real-time alerts to pedestrian workers and equipment operators during hazardous proximity situations, and the Bluetooth technology’s audible alert sound can be distinguished from other common equipment alarms and roadway work zone site noises. Furthermore, it offers wireless and rugged technology that can withstand the harsh conditions of an outdoor roadway work zone.
Evaluation of Work-Zone Safety Technologies in Highway Construction
Owing to a lack of tools for making informed decisions, the majority of construction contractors take a cautious approach to safety technology adoption. When the wrong safety tools are used on the job, or when the right tools are used incorrectly, workplace safety is jeopardized. Chuma Nnaji of the University of Alabama developed a practical demonstration of how evaluation protocols are used to make decisions about whether or not to adopt a safety technology for work-zone construction and maintenance operations to enable construction employers to use the right tools for the right job. The protocol consisted of five steps, each of which offered valuable information to aid in making informed decisions about the implementation of work-zone protection technologies. These steps are as follows:
- Technological documentation
- Current Practices Survey
- Selected Technology Pilot Testing
- Technology Selection for Live Testing
- Selected technologies’ implementation and re-evaluation
These measures can be used during the procurement process for the right technical device for construction work.