Abstract: The invention relates to a method of visually representing the variation over time of a difference between a real value of a parameter and an optimum value thereof using at least three activatable light signals, said method comprising: a first transition step (105) that is performed if the current range of values is contiguous with a prior range of values, in which step, after a first delay has elapsed, the signal associated with the prior range of values is deactivated and the light signal associated with the current range of values is activated; and a second transition step (107) that is performed if the current range of values is not contiguous with the prior range of values, during which step, after a second delay has elapsed, the light signal associated with the prior range of values is deactivated and the light signal associated with an intermediate range of values corresponding to a range of values contiguous with the prior range of values, is activated, and then after a third delay has elapsed, the

Abstract: The invention relates to an autonomous wheeled vehicle (100; 200) having a driver's cabin (16) and a space (18) for transporting passengers and/or objects, to a coupling procedure, to an uncoupling procedure, and to a method of managing said vehicles, and also to the resulting vehicle train. In characteristic manner, the vehicle includes: a steering front axle (12); a retractable coupling system (22) comprising a first portion (221) situated at the front of the vehicle (100; 200) and a second portion (222) situated at the rear of the vehicle (100; 200), the first portion (221) of one vehicle (100; 200) being suitable for co-operating with the second portion (222) of another vehicle (100; 200) when the coupling system (22) is extended, so as to connect the vehicles (100; 200) together by forming a coupling between them; and also protector means for protecting said coupling. The invention is applicable to buses.