Japan decided Tuesday to allow highly autonomous "level-4" self-driving vehicles to be used for transit and delivery services from April 2023.

Private cars will not be subject to the changes next year, with limited adoption of the automated vehicles intended to lead to the technology's use in unmanned bus services in regions with falling populations and in self-driving delivery robots.

Self-driving automation is classified into five levels starting at level-1, which allows either steering, brake or acceleration support.