In a road race, a group of cyclists often follow one another in a line to reduce the aerodynamic drag and improve energy efficiency. This technique, known as platooning, has been used for decades in the sport of cycling. Today, the time-tested technique is making a huge footprint in the innovative transportation industry with the rise of automated heavy-truck platoons.
Grouping heavy trucks in the same lane with short following distances can increase road capacity, save fuel, reduce greenhouse gas emissions, and improve safety. These benefits can only be achieved if the vehicle platoon functions in an automated, coordinated manner.
What was unknown about these automated platoons, however, was precisely how far the trucks needed to be from one another to reap the benefits, while still maintaining safety.
A team of advanced vehicle technology experts at Volpe studied truck following behavior on behalf of the Federal Highway Administration (FHWA) to provide baseline statistics for researchers to determine the optimum following distances in automated truck platoons.
The team used naturalistic driving datasets—taken from prior field operational tests of crash avoidance systems—that contain objective data showing how truck drivers drive on freeways in the real world. The results quantified how trucks follow other vehicles in various environmental conditions and at different travel speeds, and how closely a truck follows a lead vehicle when other vehicles cut in.
No other study to date examines the real-world following behavior of heavy trucks on freeways in support of automated truck platooning design, and takes into consideration weather conditions or cut-in behavior from other vehicles, or evaluates the rear-end crash risk of different following distances.