A research team at the University of Tokyo began testing a Level 4 autonomous driving bus on public roads in the Tokyo metropolitan area for the first time on Tuesday.

Levels of automation are measured between 1 to 5, with Level 1 referring to technologies that assist a driver, such as adaptive cruise control, while Level 5 is complete automation.

As part of their research, the team has been testing a Level 2 bus 〞 partially automated driving 〞 on the route that connects the university＊s Kashiwa campus to its nearest station, the Kashiwanoha-campus station, since the end of 2019.

Starting Tuesday, the bus will travel through a section of the 2.6 kilometer route 〞 approximately 700 meters 〞 with Level 4 automation, which refers to driverless operation within a defined area. The rest of the route will remain Level 2, requiring a driver.

The bus has a maximum speed of 40 km per hour and is equipped with 11 cameras and 5 Lidar systems, or technologies that can measure distance and create real-time 3D maps of surrounding areas.

Kimihiko Nakano, a professor at the University of Tokyo and lead member of the project said that finding the right balance between safety and human-like driving was key.

※If the system prioritizes safety alone, it tends to drive very slowly,§ Nakano said. ※However, this route has heavy traffic, so driving too slowly can inconvenience other drivers.§

※The difficulty was ensuring that the system maintains safety while operating in a manner close to human driving, such as making appropriate decisions about speed, right turns, and passing through crosswalks 〞 and having the machine handle those judgments,§ he added.

This is the first time a Level 4 vehicle has been employed on public roads in the Tokyo metropolitan area, which includes Tokyo, Kanagawa, Chiba and Saitama prefectures.

Four roundtrips are scheduled to be made per day and will begin operating three days a week, available for use by students and those affiliated with the university.

The latest development is thought to be another step toward addressing Japan＊s driver shortage.

However, regulatory hurdles around safety limit testing on a larger scale. Nakano and his team hope to expand Level 4 operations to the entire bus route, which is currently confined to a select area.

Although other projects have also had a Level 4 midsize bus running, such as in the Osaka Expo, the research team says that the incorporation of their vehicle into a regular bus route with a significant amount of traffic makes it unique.

Eight other projects have successfully implemented Level 4 automation across the country. Other autonomous driving projects, such as the one in Haneda Innovation City, is limited to the perimeters of their facility while others feature smaller vehicles.