A method of platoon management by a first vehicle relative to one or more other vehicles (420, 430, 440) travelling together to selectively operate the first and one or more other vehicles (420, 430, 440) in a platoon, the method comprising: within the first vehicle: monitoring through intra-vehicle communication a first safety and/or efficiency parameter of the first vehicle; monitoring, through inter-vehicle communication between the first vehicle and a second vehicle of the one or more other vehicles (420, 430, 440) leading the first vehicle, a second safety and/or efficiency parameter of the second vehicle; determining as a relative capabilities parameter a magnitude of a difference between the first safety and/or efficiency parameter of the first vehicle and the second safety and/or efficiency parameter of the second vehicle; comparing the relative capabilities parameter with a predetermined capabilities threshold; and in accordance with a result of the comparison between the relative capabilities parameter and predetermined capabilities threshold: for a first result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be a capable platoon leader vehicle relative to the first vehicle and, when not already in a platoon with the second vehicle, generating a JOIN signal for use by the first vehicle to assume a following role in a platoon relative to the second vehicle, or for a second result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be an incapable platoon leader vehicle relative to the first vehicle and, when already in a platoon with the second vehicle, generating a SPLIT signal for use by the first vehicle to discontinue the following role in the platoon relative to the second vehicle. monitoring through intra-vehicle communication a first safety and/or efficiency parameter of the first vehicle; monitoring, through inter-vehicle communication between the first vehicle and a second vehicle of the one or more other vehicles (420, 430, 440) leading the first vehicle, a second safety and/or efficiency parameter of the second vehicle; determining as a relative capabilities parameter a magnitude of a difference between the first safety and/or efficiency parameter of the first vehicle and the second safety and/or efficiency parameter of the second vehicle; comparing the relative capabilities parameter with a predetermined capabilities threshold; and in accordance with a result of the comparison between the relative capabilities parameter and predetermined capabilities threshold: for a first result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be a capable platoon leader vehicle relative to the first vehicle and, when not already in a platoon with the second vehicle, generating a JOIN signal for use by the first vehicle to assume a following role in a platoon relative to the second vehicle, or for a second result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be an incapable platoon leader vehicle relative to the first vehicle and, when already in a platoon with the second vehicle, generating a SPLIT signal for use by the first vehicle to discontinue the following role in the platoon relative to the second vehicle. for a first result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be a capable platoon leader vehicle relative to the first vehicle and, when not already in a platoon with the second vehicle, generating a JOIN signal for use by the first vehicle to assume a following role in a platoon relative to the second vehicle, or for a second result of the comparison, determining the second vehicle leading the first vehicle while travelling together to be an incapable platoon leader vehicle relative to the first vehicle and, when already in a platoon with the second vehicle, generating a SPLIT signal for use by the first vehicle to discontinue the following role in the platoon relative to the second vehicle.