bikes are mechanically propelled, it just so happens that the power come from your feet.
and also:
Section 30 Road Traffic Act 1988 says: "It is an offence for a person to ride a cycle on a road or other public place when unfit to ride through drink or drugs - that is to say - is under the influence of a drink or a drug to such an extent as to be incapable of having proper control of the cycle."
bikes are mechanically propelled, it just so happens that the power come from your feet.
and also:
Section 30 Road Traffic Act 1988 says: "It is an offence for a person to ride a cycle on a road or other public place when unfit to ride through drink or drugs - that is to say - is under the influence of a drink or a drug to such an extent as to be incapable of having proper control of the cycle."
so you can get a bit drunk...