While most people are still focused on the development of fully autonomous cars by the likes of Google's Waymo, it could be lower-level forms of autonomy which could enable connected traffic systems and force changes to traffic patterns. Most cars on the street today are older cars with no automated features beyond cruise control and automatic shifting. Under the guidelines put out by the Federal Department of Transportation, these older cars are considered Level 0 Autonomous.

 

Alongside the development of increasingly autonomous vehicles, connected features could allow these cars to transfer data quickly enough to be guided into platoon formations. Cars with Level II and Level III autonomous features could be capable of using connected traffic systems, and could be vastly more affordable than fully autonomous cars in the near-term.

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The Federal Department of Transportation is debating a date in the early 2020s for requiring all new cars to require connected features. Lately, the industry has gotten ahead of the government: Ford Motor Corp declared in early 2019 all new Ford Motor vehicles will be "connected" starting in 2022. Other major auto companies are responding with timelines which will make these technologies universal on new vehicles within a few years. In 20 years, these technologies could be ubiquitous for the then-existing vehicle fleet. These developments are exciting, of course, but it is rare for progress to move easily and show up alone.

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The following stages of vehicular autonomy are based on the official descriptions from the US Department of Transportation.

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Stage 1 for Cars: Driver Assistance

 

These are vehicles which have sensors to automatically brake, other safety features. Virtually all new cars sold today are, at minimum, Autonomous Level 1. While their features can increase safety and prevent accidents, Autonomous Level 1 does not fundamentally alter how traffic moves.

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Stage 2 for Cars: Partial Automation

 

Autonomous Level 2 vehicles are able to steer, accelerate and decelerate, but the driver has to keep her hands on the wheel and her eyes on the road. A quickly increasing share of new cars sold include these features. Most major luxury brands already include these features on new cars, including Tesla, Audi, Cadillac, Mercedes-Benz, and Volvo.

 

Stage 3 for Cars: Conditional Automation

 

In addition to Level 1 and Level 2 features, Autonomous Level 3 vehicles are able to completely handle driving in some situations with no need for the driver's attention. Level 3 autonomous cars can connect to a city’s smart infrastructure (preferably 5G) and guided without human-involvement. This is where cars could be autonomous-enough to wirelessly connect to each other and smart infrastructure devices which manage traffic based on responsive equations and rules which prioritize and organize traffic flows. I call this tool at the heart of such a wirelessly managed traffic system the prioritization algorithm.

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The Federal Department of Transportation is debating internally about when to begin requiring all new cars to have connected wireless technology capable of sharing vital information and the intentions of surrounding cars. This information could grow until vehicles are guided by smart infrastructure devices along most significant roadways.

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A recent study from the University of Illinois showed autonomous cars with connected technology could be able to act as pace cars which prevent and clean up the so-called “phantom traffic” caused by human drivers, thus increasing the efficiency of streets while the usable car fleet transitions from human-driven to computer-driven.

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Stage 4 for Cars: High Automation

 

In addition to Level 1, Level 2 and Level 3 features, Autonomous Level 4 vehicles can drive on any road without being guided or having infrastructure designed in some way to guide it. This is unlikely to produce any difference in traffic movement from Autonomous Level 3 vehicles, which is why planning around Level 3 vehicles is so important. The primary difference between Level 4 and Level 3 is what happens off the major streets. With level 4, there is no need to take the wheel and drive on streets without connected traffic devices.

 

Examples of Autonomous Level 4 are the upcoming ride-sharing services like Uber, Lyft, Google’s Waymo, and GM’s Cruise.

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Stage 5 for cars: Full Automation

 

In addition to Level 1, Level 2, Level 3, and Level 4 features, Autonomous Level 5 vehicles could be able to operate anywhere, including off-road, and generally any situation.

 

Level 5 would not change traffic patterns or improve commutes over Level 4 vehicles and thus has no practical implications for connected traffic.