We used to have a "regular" - severely disabled in the 1950s by a failure to understand the fundamentals of ballistics. For a drunken bet, he undertook to jump a Ford Prefect across the gap in the road bed of an uncompleted bridge over the new A74; with no ramp, the car had no vertical velocity component to counteract gravity, so it fell like a stone, and he met the other side at windscreen level. Forty years later, he plagued our lives - and those of the police - with his invalid carriage. This was a petrol-driven contraption on which he used to putter out to the pub (about 3 miles from his cottage), get plastered, and putter back again - often via ditches and down embankments, whence we were summoned to retrieve him. The police had given up on the breathalyser (a) Because he paid no attention, (b) Because the machine was not really dangerous (except to him), and (c) Because the Sheriff couldn't understand a word the man said (head injury). One night, we were summoned (again) to the familiar sight of the buggy lying on its side in the road alongside our man. He had caught his head a severe ding on the kerb, and clearly needed to go to hospital. He was hugely fat by this time, and festooned in a sort of supportive scaffolding of steel and leather calipers, braces, neck supports, ball joints etc. He also stank to high heaven - a fact which offended the delicate sensibilities of the constabulary when we dragooned them into helping us load him. Therafter, the sergeant turned to the problem of the buggy; fair's fair - we gave the police a hand to right it, and helped them try to push it to the kerb. However, this was not to be. It was a complicated machine ,with a tiller, and incomprehensible controls built specifically for our man's particular disabilities; it was also in gear, and we couldn't figure out how to knock it into neutral. There was no point in asking the patient how to work the thing; we could understand him no better than could the Sheriff, so the committee of males withdrew to the lights at the back of the ambulance to discuss the problem in a logical (of course!), masculine manner. Meanwhile, the one lady PC decided to hop on board, and turn the ignition key. Working as advertised, the machine started up and shot into the night, at full throttle, its little automatic gearbox changing up as it went. In hanging on, the policewoman was holding the throttle wide open, and she had no idea how to work the brakes (I believe that you had to push the tiller down). Furthermore, steering a vehicle with a tiller requires practice - and she hadn't had any. With her colleagues in hot pursuit, she travelled about 75 yards before encountering a convenient lamp-post, which the vehicle attempted to climb. This manoeuvre had the double effect of stalling the engine, and unseating the driver. Fortunately, all that was injured was her dignity. And the buggy had parked itself neatly on the pavement!