Is CAN half or full duplex?

Question

Is CAN (Controller Area Network) half duplex or full duplex communication? And what is the rationale why?

Is there an ISO CAN document which would clear up my confusion?

Answer 1

CAN has a single sender with priority arbitration. If two or more nodes attempt to send simultaneously, any nodes transmitting a lower priority ID will stop transmitting during the arbitration phase.

If your definition of "full duplex" is two transmitters able to send a message concurrently, then CAN does not meet that definition.