The Spectrum of Self-Driving Cars

Posted by

Automation is finding its place across every industry, including the transportation sector. Driverless vehicles have gone from science fiction to reality in just a few decades. Basic automotive technology has advanced to the point that the bar for standard car accessories jumped from power door locks to rear-view cameras. We may still be decades away from the flying DeLorean, but self-driving cars are here…kind of.

Google prototype of an autonomous car.

Driverless cars still have a ways to go. These completely autonomous vehicles are largely in testing phases and only operate in highly-controlled, well-mapped environments. As Aarian Marshall wrote in an article for Wired magazine, “Most developers believe it will take decades to build a car that can drive anywhere it pleases, like humans do today—if it ever happens at all.”

With this once-distant phenomenon now becoming a reality, it’s important to understand the spectrum of self-driving cars. Luckily, the Society of Automotive Engineers has created a standard for measuring the varying degrees of driverless technology in vehicles on the road today and in the future.

The SAE’s “Levels of Driving Automation” standard is on a scale of zero to five. A vehicle with little to no automation would register a zero while a completely autonomous vehicle would rate at a five.

Levels of Automation courtesy of the Society of Automotive Engineers

Find out where your vehicle ranks on the SAE J3016 Levels of Driving Automation scale:

 Level 0: No Automation

An article by The National Highway Traffic Safety Administration designates a Level 0 vehicle as having little to no automation. In this classification, the driver has full manual control over all aspects of the car including steering, accelerating and braking. Level 0 vehicles include those that have warning features such as blind spot monitoring, lane departure alerts and automatic emergency braking. Most vehicles on the road today fall within this category.

Level 1: Driver Assistance

Level 1, or, Driver Assistance vehicles are still controlled by the driver but use an advanced driver assistance system (ADAS) to aid in steering or braking/accelerating, but not both at the same time.  The Adaptive Cruise Control feature we see in many new vehicles today is a common example. With Adaptive Cruise Control, the driver controls steering while the ADAS regulates speed. Another Level 1 feature is lane-keeping or lane centering technology. The distinction here is that only one driving function is automated. Many of today’s new vehicles offer these features as options.

Level 2: Partial Automation

In a 2018 article for Forbes, Robert Szczerba summarizes the standard operating procedure for a Level 2 vehicle: “Hands off the wheel, eyes on the road, mind on the situation.” Partial Automation assigns the ADAS responsibility of both steering and accelerating/braking of the vehicle while the driver monitors conditions, ready to take control if needed. The technology is still in its infancy, so human intervention is still necessary to serve as a sentient set of lane bumpers, keeping the vehicle out of the gutter if it can’t do so on its own. Some current examples include Cadillac Super Cruise and Tesla Autopilot.

Level 3: Conditional Automation

Conditional Automation represents a step up on the SAE’s scale and a step down in driver involvement. According to the NHTSA’s interpretation, “the driver is a necessity, but is not required to monitor the environment. The driver must be ready to take control of the vehicle at all times with notice.” Theoretically this could allow you to take your eyes off the road for extended periods of time and free you up to do things like work on a computer or read a book.

Level 4: High Automation

Moving further along the scale, High Automation renders a vehicle capable of all driving functions including steering, braking and monitoring its environment in certain situations. In Level 4 automation the scenarios for human intervention are minimized even further.

Level 5: Full Automation

At Full Automation, the vehicle can perform all driving functions and, unlike Level 4, maneuver all road conditions. Level 5 is the only class that does not require human intervention. In some instances, these vehicles may not feature traditional driving controls such as steering wheels and gas pedals. (Don’t panic, humans will still likely be able to override the ADAS and take control of Level 5 vehicles.)

As with any groundbreaking technology, self-driving cars will have to ride the product adoption curve and the timeline for their arrival to the majority remains uncertain. For now, most vehicles on the road have little to no automation.

Visit and search our inventory of over 100,000 Level 0 and Level 1 vehicles!

Leave a Reply