Roadway work zones are hazardous both for motorists who drive through the complex array of signs, barrels, and lane changes and for workers who build, repair, and maintain the streets, bridges, and highways. Most worker fatalities are due to being struck by a vehicle in the work zone. Pickup trucks and SUVs accounted for 151 worker deaths at road construction sites from 2011-2017, followed by machinery (131), automobiles (129), semi-trucks (124), and dump trucks (82).
A blind spot (or blind area) is the area around a vehicle or a piece of construction equipment that is not visible to the operator, either by direct line-of-sight or indirectly by use of internal and external mirrors.
Construction equipment is typically large and has an enclosed cap. This can make the blind areas around the equipment very large and hard to see. The bigger the equipment, the larger the blind spots or hazardous areas for pedestrian and ground workers.
Here is a complete list of construction vehicles and blind area diagrams: Construction Equipment Visibility-Diagram Lookup.
1. What type of work zone accident accounts for most fatalities?
a. struck by a vehicleObstructions in the driver's line of sight, including mirrors, door and window posts, tools, and attachments on vehicles can create blind spots, reduce visibility, or swings that can increase the risk to workers being struck or pinned. You must know the equipment swing radius, such as how far can it reach, move, or rotate.
Ways to protect yourself when working near heavy equipment include the following:
A 33-year-old construction laborer was working at a gravel-unloading operation at a highway construction site. His usual work assignment was to operate the generator for the conveyor system that moved gravel unloaded from belly dump trailers. A dump truck driver on the site was having difficulty opening the gates of his belly dump trailer. Attempting to assist the driver, the laborer went under the trailer to manually open the gates. The driver, not realizing the laborer was under the trailer, pulled away from the unloading platform and ran over him with the rear dual tires of the trailer. The laborer was pronounced dead at the scene [Minnesota Department of Health].
2. If you're required to be near parked equipment or trucks, where should you stand to avoid being hit or run over?
a. Behind on the passenger sideAccording to BLS, between 2011 and 2015, of the 49 workers fatally struck by a dump truck, the dump truck was backing up in 40 cases.
If it is reasonable to expect employees will enter the backing zone, the vehicle must have an operable automatic reverse signal alarm which is both audible above the surrounding noise level and can be heard at least fifteen feet from the rear of the vehicle.
You must also have an observer who signals when it is safe to back up or stop or the vehicle has an operable device installed which gives the driver a full view of the area behind the dump truck.
A laborer was backed over by a tack truck while working as a flagger on an asphalt resurfacing job in a residential roadway work zone. The victim was standing with his back to the reversing tack truck when a dump truck driver attempted to warn him by waving his arms. The tack truck struck the victim; the driver thought he had passed over a manhole cover and continued backing. The tack truck driver stopped when he saw the dump truck driver running and waving his arms in his mirror. Both drivers found the victim at the front of the tack truck lying face down on a man-hole cover on the ground.
3. What must a dump truck have if it is reasonable to expect employees will enter the truck's backing zone?
a. A barricade posted to warn workersSpotters are a proven method of protecting employees on foot behind vehicles with an obstructed view, but spotters themselves can be at risk for injury or even death. Employers can implement the following actions to help keep spotters safe:
4. What must a vehicle driver do while the vehicle is in motion if the spotter is out of the field of view?
a. Call the spotterNote: The following solutions are not required by any OSHA standard. They are provided for informational purposes only.
Most vehicles (and some types of mobile equipment) can accommodate a camera that provides operators with a view to the rear. Some vehicles come equipped with cameras or may be offered with them as optional equipment. Camera systems can also be purchased as after-market equipment for vehicles.
Viewing screens may be dash-mounted but must not block the driver's view out the windshield. Harsh environments, such as some construction sites or mines, may require more rugged cameras. Determining where to mount a camera for maximum effectiveness may be difficult, especially on large vehicles. For example, dump trucks may require two or three cameras to monitor the blind spots on the front, rear, and side of the vehicle.
These systems alert the driver with a visual and/or audio warning. These systems must be positioned so that they won't detect harmless objects, such as the concrete slab of a driveway, which can interfere with the detection of an object or person behind the vehicle or mobile equipment. Like cameras, this equipment can be mounted on most vehicles and may be an option from some equipment manufacturers.
Radar systems transmit a signal, which is bounced off an object. The signal is then received by a receiver. The composition of an object can affect detection, with some materials being virtually invisible to radar.
Ultrasonic systems, such as sonar, emit bursts of ultrasonic waves in a frequency above the hearing threshold of humans. When the waves strike an object, they generate echoes used to determine the distance to the object. These systems alert the driver with a visual and/or audio warning.
5. What is a weakness inherent in the use of radar detection devices as a backup safety system?
a. The composition of objects does not affect detectionTag-Based Systems. Another type of proximity detection system is an electromagnetic field-based system, which is a type of tag-based system. This system consists of electromagnetic field generators and field detecting devices.
These electromagnetic field-based systems can be programmed to warn affected workers, stop the vehicle, or both, when workers get within the predefined danger zone of the vehicle.
6. Which of the following backing safety solutions uses electromagnetic field generators and field detecting devices?
a. Cell-phone application systemRead the material in each section to find the correct answer to each quiz question. After answering all the questions, click on the "Check Quiz Answers" button to grade your quiz and see your score. You will receive a message if you forgot to answer one of the questions. After clicking the button, the questions you missed will be listed below. You can correct any missed questions and check your answers again.