Japan's transport ministry has compiled its first guidelines for introducing self-driving trains.
Ministry officials announced the guidelines on Tuesday.
The ministry's expert panel discussed automated train operations out of concern over a shortage of drivers due to the country's shrinking and aging population. Local railway companies are faced with particular challenges, including difficulty securing drivers.
The guidelines feature technical requirements for automated operations to ensure safety at the same level as trains controlled by drivers.
The three automation levels include trains operated without any staff on board, those with crew members on the train in case of emergency, and those with train staff on hand in the front car.
For the first two levels, the guidelines ask for safety measures, such as installing platform barrier doors, obstacle detection sensors and fences to prevent trespassers on the line.
The guidelines also point out that the third level will require train staff to conduct safety checks before starting and to make emergency stops. Such trains will also need an advanced automatic stop system.
Ministry officials plan to draw up rules with the railway operators based on the guidelines.