A vehicle comprising a chassis, a seat mounted on the chassis, as well as a right running gear and a left running gear, each running gear being mounted on the chassis and including a front wheel and a rear wheel, the vehicle defining a longitudinal direction, a transverse direction and a vertical direction in the neutral position, wherein: - the chassis includes a cross member located in the vicinity of a median vertical transverse plane of the vehicle; - each running gear includes, for each of the front and rear wheels, at least one arm which is arranged substantially parallel to the mean plane of the wheel, each arm having one end linked to the axis of the wheel (5, 6) and another end mounted on a connecting part in a pivoting manner about a pivot axis which, in the neutral position, is disposed substantially in the plane of the wheel (5, 6) and is vertical or inclined downwards in the direction of the wheel (5, 6), the connecting part being mounted on the cross member of the chassis; - the seat is mounted on the chassis by a first assembly device configured to allow the rotation of the seat relative to the chassis about a longitudinal axis; - the vehicle comprises four coupling members, each coupling member connecting the seat and one of the arms linked to the axis of a wheel (5, 6); the vehicle being devoid of axles; characterized in that the first assembly device is configured to bias the seat elastically towards the neutral position, and in that the vehicle is configured so that the rotation of the seat relative to the chassis causes, via the four coupling members, the pivoting of each wheel (5, 6) about the pivot axis, that is to say: - on the one hand the steering of the wheel (5, 6) relative to a vertical longitudinal plane; - and on the other hand the inclination of the mean plane of the wheel (5, 6) relative to the longitudinal vertical plane of the wheel (5, 6) in the neutral position, inwards the turning, if the pivot axis is not vertical in the neutral position; the direction of the vehicle being controlled by the simple rotation imparted to the seat. - the chassis includes a cross member located in the vicinity of a median vertical transverse plane of the vehicle; - each running gear includes, for each of the front and rear wheels, at least one arm which is arranged substantially parallel to the mean plane of the wheel, each arm having one end linked to the axis of the wheel (5, 6) and another end mounted on a connecting part in a pivoting manner about a pivot axis which, in the neutral position, is disposed substantially in the plane of the wheel (5, 6) and is vertical or inclined downwards in the direction of the wheel (5, 6), the connecting part being mounted on the cross member of the chassis; - the seat is mounted on the chassis by a first assembly device configured to allow the rotation of the seat relative to the chassis about a longitudinal axis; - the vehicle comprises four coupling members, each coupling member connecting the seat and one of the arms linked to the axis of a wheel (5, 6); the vehicle being devoid of axles; characterized in that the first assembly device is configured to bias the seat elastically towards the neutral position, and in that the vehicle is configured so that the rotation of the seat relative to the chassis causes, via the four coupling members, the pivoting of each wheel (5, 6) about the pivot axis, that is to say: - on the one hand the steering of the wheel (5, 6) relative to a vertical longitudinal plane; - and on the other hand the inclination of the mean plane of the wheel (5, 6) relative to the longitudinal vertical plane of the wheel (5, 6) in the neutral position, inwards the turning, if the pivot axis is not vertical in the neutral position; the vehicle being devoid of axles; characterized in that the first assembly device is configured to bias the seat elastically towards the neutral position, and in that the vehicle is configured so that the rotation of the seat relative to the chassis causes, via the four coupling members, the pivoting of each wheel (5, 6) about the pivot axis, that is to say: - on the one hand the steering of the wheel (5, 6) relative to a vertical longitudinal plane; - and on the other hand the inclination of the mean plane of the wheel (5, 6) relative to the longitudinal vertical plane of the wheel (5, 6) in the neutral position, inwards the turning, if the pivot axis is not vertical in the neutral position; - on the one hand the steering of the wheel (5, 6) relative to a vertical longitudinal plane; - and on the other hand the inclination of the mean plane of the wheel (5, 6) relative to the longitudinal vertical plane of the wheel (5, 6) in the neutral position, inwards the turning, if the pivot axis is not vertical in the neutral position;