Help is at hand for British motorists in the United States to keep them from getting stuck on the dual carriageway with a bad silencer and not a spanner in the boot.

"Driving in the U.S.A.," a 32-page pamphlet written by two British journalists, aims to dispel some of the mystery of motoring the American way, and to protect this year's crop of self-driving British vacationers from death, speeding fines and big lawsuits.The pamphlet is another of those occasional reminders that the potential for Anglo-American misunderstanding is enormous, especially on the highways. They drive on opposite sides and have little in common other than that both use miles instead of kilometers.

The dictionary alone takes up 1 1/2 pages: a trunk is a boot; a hood is a bonnet; a wrench is a spanner; a muffler is a silencer; a stickshift is a gearshift, a fender is a bumper; gas is petrol; a trailer is a caravan; a divided highway is a dual carriageway and a beltway is a ring road.

Some words don't even have a British equivalent. Thus gridlock is translated laboriously as a "traffic jam in all directions."

The booklet is filled with surprises as to how much Britons don't know about American driving, such as toll roads, the fact that cars with automatic transmissions "creep forward" if the brake isn't pressed, and that speeding can mean fines.

Under the heading "The American Policeman," motorists are told:

"Treated with courtesy and respect, the American `cop' will be polite, even friendly in a wary sort of way. His (or increasingly her) job is to enforce the law, prevent crime - and survive. American police, with good reason, fear for their lives."

With 400,000 Britons going on driving vacations in the United States this summer, "there's a lot of potential for mayhem, a lot of people who will drive out of petrol stations onto the wrong side of the road," Symonds said.