While truly driverless trucks are not likely to appear in any significant numbers on American highways before 2030 or even later, the technology to achieve fully automated commercial vehicle operation is substantially in place right now. Within the next two years, the first steps toward automated driving are expected to become a common feature of interstate trucking, at least in some places and under certain traffic and weather conditions.
To understand how automated driving is likely to spread throughout the trucking industry and the interstate highway system, it’s important to understand that automated vehicle operation systems are designed to function at one or more designated levels of automation, from Level 0 (no automation) to Level 5 (fully driverless operation under any traffic or weather conditions).
The Society of Automotive Engineers International (SAE) developed its six-point scale of automation in 2014. Over the last two years, the SAE levels have come into widespread use both within the industry and among government regulators. Under recent guidance from the National Highway Safety Administration, manufacturers are expected to test and certify automated vehicle performance and safety at a given level of automation as defined by the SAE.
SAE International Levels of Automation
The following list briefly describes the characteristics of automated driving at each of the SAE levels:
Level 0, No Automation: This baseline level assumes no technological assistance to driving in terms of both operational (e.g., steering, accelerating, braking) and tactical decisions (e.g., lane changes or response to hazards or other traffic behavior). When a vehicle is fully controlled by a human driver, it’s operating at SAE Level 0, even if the driver’s operation is enhanced by onboard cruise control or automated warning systems.
Level 1, Driver Assistance: This first level of automated driving assumes that the human operator monitors the road and keeps steering control, but benefits from automated assistance in acceleration, deceleration and braking. Through vehicle-to-vehicle communication software, trucks can follow one another at extremely short distances at SAE Level 1 automation. If you ever see two or three trucks traveling together at following distances of 20 to 50 feet, you can be sure that they’re operating under SAE Level 1 at a minimum.
Level 2, Partial Automation: At Level 2, the driver remains responsible for watching traffic and responding to system prompts, but the automated driving software will handle all steering, braking and acceleration tasks. Drivers at SAE Level 1 can keep their feet off the pedals, and at Level 2 they can keep their hands off the wheel as well.
Level 3, Conditional Automation: This middle level of automation represents a significant step toward driverless operation. At Level 3, the driver need only stay ready to resume operation of the vehicle when instructed by the system. Until then, the driver has no need to steer, brake, accelerate or watch the road –- no hands, no feet, no eyes.
Level 4, High Automation: The driver has essentially no responsibility for operating the vehicle at Level 4. The automated system will not only take care of all operational and tactical decisions related to driving, it will also revert to a failsafe condition, such as stopping on the shoulder, without human intervention. Vehicles operating at Level 4 can only do so under certain conditions, such as clear weather or light traffic.
Level 5, Full Automation: Vehicles operating at Level 5 might well be doing so without a driver – they can handle all driving tasks, including failsafe maneuvers, under any traffic or weather conditions. No vehicle is expected to be certified for SAE Level 5 operation at any time soon.
Any manufacturer interested in the highly automated vehicle market must test and certify its products for performance and safety at one or more of the SAE levels of automation. In other words, a truck will be certified for operation at a given automation level without the need for regulatory approval, at least under current federal rules.
Vehicles can also be produced to perform at different levels of automation under different circumstances. It won’t be long before a truck can operate under SAE Level 1 or 2 on the highway, but switch to Level 4 at the loading dock or freight yard.
In the near term, automation at Levels 1 and 2 is expected to appear in trucking operations on low-traffic divided highways throughout the United States. Although the higher autonomy that characterizes operation at Levels 3 to 5 is still a decade or more away, Level 4 driverless trucks have been in use for several years already in remote mining operations in Australia, Canada and Chile.
In the United States, “driver assistive truck platooning”, or DATP, will probably be the first widespread application of automated vehicle technology. Operating at Level 1 or 2, DATP trucks will be able to realize significant fuel savings and emissions reductions through closely coordinated acceleration, deceleration and braking maneuvers in which the lead truck effectively controls the speed and following distances of the trailing trucks. With following distances as low as 40 or 50 feet, DATP trucks can also be expected to reduce highway congestion by minimizing the amount of space trucks need for safe operation.
Is Driverless Technology Running Ahead of State and Federal Regulation?
The federal government so far has shown little inclination to stand in the way of highly automated vehicle technology, but state governments and motor vehicle departments are a different story. Some states, such as California, Nevada and Michigan, are actively encouraging the development and adoption of vehicle automation, while others are not.
For example, the Missouri legislature last year passed a bill that would have allowed testing of DATP operations on the state’s roads, but it was vetoed by the governor, mainly out of concern for the short following distances that trucks need to maintain to realize the economic and environmental benefits. Time will tell whether the fuel economy, emissions reduction and safety advantages of highly automated vehicle operation will overcome the resistance of some policymakers to this emerging technology.