Each year over 20,000 injuries and over 120 fatalities occur at road construction projects. Many incidents result from equipment that is backing up (reversing) or drivers inadvertently traveling into the work site. One tool now used for protection involves truck-mounted attenuators (TMAs). These are vehicles used as a physical obstacle that protect construction teams by blocking potential threats. Terry O'Sullivan, president of the Laborers Health & Safety Fund of North America, explains that remotely operated TMAs are designed to be struck and protect the otherwise vulnerable road crew. Having someone on board in a TMA is obviously dangerous.
In Colorado, there were 26 times when a driver collided with a TMA over the last four years. Usually there is no TMA occupant necessary when blocking fixed work sites; however, often the projects involve tasks such as paving, where the team is moving. The Colorado Department of Transportation (CDOT) has begun operating these vehicles remotely. Shailen Bhatt, the CDOT director, says trucks designed to serve as barricades are not good places for human occupants.
The ability to control the TMA remotely is possible by using technology common in “driverless” cars that are in development. Companies leading these efforts include Google, Tesla, and Uber. The vehicles are equipped with cameras, onboard computer systems, and sensors that are capable of determining the relative position of the car and those traveling near it. They are also able to recognize traffic signals, signs, and pedestrians as well.
A driverless TMA was employed on a recent construction project where a moving team was painting road stripes in Colorado. So far, this method has proven to be a good solution to improve road worker safety. Autonomous features continue being integrated into newer vehicles. Features that warn drivers of potential approaching roadway obstructions are increasingly common and even have the ability to automatically stop the vehicle to avoid a collision. Lane-assist technology is used to alert drivers when their vehicle veers outside their lane of travel.
The current means of classification for vehicles with autonomous or driverless capabilities consists of five levels:
- Level 1: Capable of activating a single automated function at a time such as automatically engaged brakes or cruise control
- Level 2: Capable of simultaneously executing two functions such as steering or braking; these vehicles do require a driver
- Level 3: Capable of executing many automated functions, with a driver assuming control when prompted to do so
- Level 4: Capable of operating in a driverless mode in the majority of environments, with the option of driver assistance
- Level 5: Fully functional without the need for a vehicle occupant
Those who work at roadway construction sites may encounter dangerous scenarios, particularly when along highways where motorists are traveling rapidly. As autonomous vehicle technology continues to evolve, there is a significant opportunity for further work zone safety enhancements. The goal in the short-run is to provide a shield to road workers without requiring a human to be positioned in a dangerous situation.