Autonomous Driving in Restricted Areas at Japanese Airports

By Yoshihiro Fujimaki

1. What is “autonomous driving in restricted areas”?

Development of the autonomous driving car is progressing not only for public roads but also for airport environments. It looks easier to ensure traffic safety in restricted areas of airports, so-called “Airside,” than on public roads because neither the general public nor cars driven by them are present. In addition, while the Japanese government has set an aspirational target of 60 million inbound tourists in 2030, the capacity of airports may be constrained by a shortage of labor working at airports, especially those working for ground handling services. Therefore, autonomous driving cars at airports are expected to be a quite useful tool for labor-saving.

Based on the above circumstances, in 2018, the Japan Civil Aviation Bureau (JCAB) established a committee to study demonstration experiments of autonomous driving in airport restricted areas. This committee aims to realize autonomous driving in restricted areas by conducting several demonstration experiments. Since its establishment, the committee has been considering the guidelines, selecting participants, and reviewing the results of such demonstration experiments. The committee focuses on towing tractors and ramp buses, some of which are currently at “Level 3” autonomy and will be at “Level 4” autonomy in the future. The differences between “Level 3” and “Level 4” in autonomy are shown in the table below.

Table 1: Differences between “Level 3” and “Level 4” in autonomous driving (Prepared based on “Public-private ITS Initiative/Roadmaps 2020” (in Japanese, definitions of these Levels are equivalent to SAE International J3016 (2016)): https://cio.go.jp/sites/default/files/uploads/documents/its_roadmap_2020.pdf)

2. Autonomous driving towing tractor

Towing tractors are used for transporting passenger checked baggage and other cargo within the airport. Serving as the demonstration experiments which I mentioned earlier, All Nippon Airways (ANA) and Japan Airlines (JAL) have been conducting several trials of autonomous driving towing tractors.

ANA has been holding tests at Tokyo International Airport (Haneda Airport). Their autonomous driving towing tractor is manufactured by Toyota Industries Corporation, and it runs along the pre-defined route based on information gathered from camera, GPS and Laser imaging Detection and Ranging (LiDAR) integrated sensors. In FY2021, they performed over 200 transportations of passenger checked baggage and other cargo, over 1,100 km in total, without any delay.

JAL has been conducting tests at Narita International Airport. Their autonomous driving towing tractor is manufactured by TLD Group, and it also runs along pre-defined route based on information from odometer, inertial measuring unit (IMU), GPS and LiDAR sensors. In FY2020, they performed over 300 transportations of passenger checked baggage, over 300 km in total, and have officially introduced the autonomous driving towing tractor since March 2021. 

(The above figure is reprinted from the JAL’s website: https://press.jal.co.jp/en/release/202103/005973.html)

3. Autonomous driving ramp bus

Ramp buses are used for transporting passengers between airport terminal buildings or between airport terminal buildings and aircraft. An autonomous driving ramp bus is now undergoing demonstration experiments at Narita International Airport.

That autonomous driving ramp bus is for 10 passengers, and is manufactured by Tajima Motor Cooperation with autonomous driving system developed by TIER IV, which is a software development company in Japan. It runs along the pre-defined route based on information from camera, IMU, GPS and LiDAR sensors, and ran in total for about 80 km in 4 days for a demonstration in FY2021. Currently, the consortium including Narita International Airport Corporation and TIER IV is conducting trials where a single remote supervisor monitors up to three vehicles at the same time.

(The above figure is reprinted from the Narita International Airport Corporation’s website (in Japanese: https://www.naa.jp/jp/docs/20220210-5g_HP.pdf)

4. Towards “Level 4” autonomy

Besides vehicle development, several challenges regarding infrastructure and traffic rules still remain in order to realize “Level 4” autonomous driving in airport restricted areas. Particularly in restricted areas, generally there are no traffic lights at intersections and tall traffic lights may become a hazardous obstacle to aircraft in those locations  . Regarding this point, it is still under consideration for how to ensure traffic safety using infrastructure and/or traffic rules. JCAB has set the target to realize “Level 4” autonomous driving both for towing tractors and for ramp buses by 2025, and continues working with the participants of demonstration experiments.