Well, the only method that we can be sure works is by price. A high price
will force users to judge how necessary their flight is. Just look at the
drop in traffic after congestion traffic, all of these journeys that were
"absolutely essential" or "could not be made any other way" were obvious not
essential enough to warrant £5 expenditure.



Yes but it still stands that a lot of things are un-neccessary and
cause damage. Especially drug taking, smoking and drinking. But I
don't see the liberals and enviromentalists trying to ban these three.