In the most recent issue of our Focus newsletter, we briefly mentioned a proposal to create dedicated autonomous vehicle lanes to accommodate Foxconn trucks from Mitchell Field in Milwaukee to Mount Pleasant in neighboring Racine County. Space limitations prevented more discussion of autonomous vehicles and their possible impact in Wisconsin.
The term “autonomous vehicle” conjures images of self-driving, robotic, unmanned vehicles zipping down the highway. There are several levels of automation, however, including some that are not quite as futuristic. Indeed, the automated vehicle community has adopted five levels of automation for ease of discussion.
While it is not yet clear which direction Foxconn and the Wisconsin Department of Transportation may take with regard to automation here, the most futuristic approaches are not yet realistic. Instead, some companies — such as Foxconn suppliers — may turn to more basic automation levels, including truck “platooning,” which is the practice of electronically “coupling” multiple trucks together to significantly shorten gaps between vehicles. This practice makes it possible to reduce emissions, save energy, and enhance safety.
Driver Assisted Truck Platooning (DATP) is a specific form of truck platooning in which connected follower vehicles operate in conjunction with a lead vehicle. The driver in the lead vehicle drives normally, controlling steering, braking, and acceleration. The drivers in connected vehicles are only responsible for steering laterally. The connected vehicles automatically match the acceleration and deceleration of the lead vehicle. However, the driver in each vehicle maintains the ability to take over acceleration and braking at any time
Truck platooning has various benefits, but chief among them is the potential for increased efficiency. Because acceleration and deceleration are controlled by one source — the lead driver — no delay exists. Therefore, instead of following each other hundreds of feet apart, heavy trucks can travel full speed at as little as 30 feet apart, creating less wind resistance and increasing fuel efficiency. Depending on following distance, gross vehicle weight, and average speed, combined fuel savings can range from 3% to 15%. International studies have shown an even higher range of potential savings.
Safety is an obvious concern when discussing automated vehicles, but even more so when talking about an automated platoon of freight trucks. While truck platooning is not explicitly designed to prevent collisions, the technological systems in place can greatly reduce the frequency and severity of front and rear-end collisions. Automated longitudinal control eliminates human delay when responding to sudden unsafe conditions. Numerous studies have shown reductions ranging from 60% to 71% in unsafe behavior and hard braking.
Since truck platooning is a relatively new technological innovation, many states do not have statutes addressing implementation. That’s not the case in Wisconsin, however. Due in part to expected traffic from Foxconn, the Wisconsin Assembly passed legislation that changed requirements specifically for heavy trucks in a platoon. Prior to this legislation, a heavy-truck driver had to operate with a minimum following distance of 500 feet, and the truck driver needed to leave sufficient space so that a passing vehicle could enter without danger. The new state law provides an exception to this statute for heavy trucks operating in a platoon.
With growing concerns about transportation funding, new technologies and methods of transport are becoming more important. A reduction in collisions and an increase in fuel efficiency are a few of the potential benefits of heavy truck automation.