Kagawa Takes Automated Driving Vehicle Ride on the Tokyo Metropolitan Expressway (Part One)


Welcoming Kagawa to TRI-AD was its CEO, Dr. James Kuffner, and CTO, Ken Koibuchi.

Of course, one of the first things Kagawa was burning to ask was what makes TRI-AD unique.

“Previously, I visited TRI in Silicon Valley as well as Toyota’s Higashi-Fuji Technical Center. After comparing the two, I can see that it is different from what I already see here at TRI-AD. Can you explain the differences?”

Dr. Kuffner’s response was clear.

“Here at TRI-AD, we’re trying to take the research prototype and actually make a real product,” he said.

Basically, he was saying that TRI-AD is creating the bridge between prototypes and products. More specifically, it is taking the automated driving technology being researched and developed at TRI and Higashi-Fuji and determining how to put that technology into cars that actually drive on public roads.

“I am eager to ask when we might start seeing automated driving vehicles available in the market,” asked Kagawa.

“The reality is, you can drive today,” Dr. Kuffner replied with a smile. “Really!? You mean I get to ride in a driverless automobile, today?” responded a slightly confused Kagawa.

Kagawa was then led to an underground carpark, where he found three people waiting for him: Tomoya Kawasaki, Director of Automated Driving Development, Nobuhiko Kawaura from the Automated Driving & Advanced Safety System Development Division, and Kenta Kumazaki, from Testing.

“All of our surnames begin with the letter ‘K’!” noted an excited Kagawa.

In the carpark was a modified version of a Lexus LS, a prototype test vehicle being developed with the aim of commercialization in the near future.

Kagawa could hardly contain his excitement: “I’ve been driving the Tokyo Metropolitan expressway for 35 years. Finally, I get to take my hands off of the steering wheel!”

Before jumping in for a ride, however, he first was given information on both the vehicle and its automated driving technologies by Kawasaki, who used charts displaying different levels.

Automated driving levels range from 0 (fully manual) to 5 (fully automated). For example, the functions currently available in new vehicles include functions like automatic emergency braking and dynamic radar cruise control and are considered Level 1. Functions up to Level 2 are classified as “driving support”, and require the human driver to supervise the autonomy. Levels 3 and higher are “automated driving.” The primary difference between the lower and upper levels is that in the lower levels, the driver still manually carries out many of the driving tasks, including constantly checking that the autonomy is working correctly, even when driver support functions are operating. For the higher levels, all driving tasks may be carried out by the system, either fully with hand-off to the driver, or fully without a hand-off to the driver ever being required (Levels 4 and 5).

When visiting TRI in Silicon Valley and Higashi-Fuji Technical Center, Kagawa experienced a prototype test vehicle equipped with a Level 4 system. Today’s test ride at TRI-AD would be a Level 2 vehicle, which required the human driver to supervise the actions of the automated system and take over when necessary.

When looking at the levels chart, Kagawa asked what level Toyota is aiming for. Kawasaki responded that Toyota aims to make cars safer through the deployment of automated driving technologies, and that the goal was to utilize appropriate technology depending on the phase.

Merging and Changing Lanes is All Fully Automated

Following that explanation, Kagawa was next invited to sit in the front passenger seat for the clearest view of the car’s capabilities. Upon departure, Kawaura piloted the car onto the expressway in anticipation of hands-free driving. After checking system operation, Kawaura removed his hands from the wheel and his feet from the pedals. The car continued to drive smoothly.

“What is this!” Kagawa exclaimed, his shout echoing throughout the car’s interior.

It was not long before the car reached the point where it would need to merge lanes. When it reached the area, the automated driving system turned on the indicator and smoothly merged into the main lane without any human input.


The system is designed to understand the surrounding situation and make sure that there is enough space to merge safely and then to proceed.


I see. If there had not been any space, would the system have slowed down the vehicle?


Yes, it would have slowed us down.


That was a well-judged entry, wasn’t it?

A short drive later, a slow car appeared in their lane.

“With the driver’s consent the car will pass on its own,” Kawasaki said and gave the car permission to pass. The car then turned on its indicators and moved into the passing lane, increasing speed and then, once it was sufficiently ahead of the other car, returned to its original lane. During this operation, the indicators, steering, and accelerator were all automatic.

Passing cars that are in front of it requires humans to approve the system’s suggestion. This is not only to confirm the driver’s intention, but also to get the driver to check properly for safety. It’s as if the driver and the car are interacting.

A little further along, they encountered a junction. Two lanes merged from the left, and they needed to bear left at the junction immediately ahead.

“It is going to be a difficult merge here,” Kawasaki noted. Even a human driver would be nervous. Nonetheless the prototype automated driving car found a space between the merging cars and changed lanes beautifully, going with the flow of traffic.


What happens when other cars try to cut you off? Will the system recognize an action like that?


Yes, it will, it is designed to reduce speed to make space for other cars.


Does the driver need to approve it?


No, it’s automatic.


Where is the line for where the system needs the driver’s approva?


Driver approval is only needed for passing other cars. Merging, changing lanes, adjusting speed, adjusting gaps—that’s all designed to be automatic.


So the point is, you need to give approval for proactive operations, but some operations related to safety are performed by the car.




That really makes a lot of sense.

“Can these automated driving systems work even at night? When it rains?” asked a fascinated Kagawa.

The simple answer, according to Kawasaki, is that both night and rain pose no problems. However, torrential rain or heavy snow can cause the sensors to stop registering, which means the human driver has to take over.

“I just can’t believe that the automobile is driving on its own on the metropolitan expressway,” said Kagawa, still astonished. Kawasaki explained how challenging it really is to drive on the expressway.


This expressway was made in time for the previous Tokyo Olympics. They didn’t have enough time to make it perfect, so the road is narrow and has a lot of curves.


Facing challenging roads like these is what helps us as we improve our technology.

Then, all of a sudden, a truck in the neighboring lane put on its indicators and moved over into the lane in front of the Lexus. The moment it did, the automated driving system reacted by quickly decreasing its speed and opening up a gap with a smoothness one wouldn’t expect from automated driving. As is custom in Japan, the truck flashed its hazards briefly to say thanks, and Kagawa grinned:

“That truck driver has no idea this is an automated car.”

It’s Not So Much Driving as Working Together

As the car sped smoothly across the Rainbow Bridge, Kagawa made the following observation:
“This feels like it’s a team effort between the driver and the vehicle instead of the driver driving a vehicle.”

Kawasaki told him that feeling is what Toyota’s teams working on the “Mobility Teammate Concept” aim to create.

TRI-AD’s CEO Dr. Kuffner explained, “The ‘Teammate’ technology that we are developing is meant to support human drivers and to help them feel comfortable and help them feel safe.”

CTO Koibuchi added: “You can see this in the Mobility Teammate Concept logo. The logo shows a human and an automated driving system both holding the same steering wheel.

“The driver and the automated driving system are both working together in the same direction to move the car … We call it an automated system, but that doesn’t mean we don’t need a human driver. We think that having a driver is very important, and even put the driver in the priority seat.”

TRI-AD is helping make a product where safe driving can be done as humans and cars partner on the same team. The test drive on the Tokyo Metropolitan Expressway was a chance for Kagawa to experience this future world that Toyota is describing.

In Part Two, Editor-in-Chief Kagawa finally visits the development offices at TRI-AD to delve deeper into the secrets of the technology that made today’s hands-free driving on the expressway possible.