The issue of rail-road competition is often clouded by subjective factors that are more a matter of partisan sophistry than scientific analysis. Paradoxically, those who believe they are defending rail transport constantly discredit it by suggesting that the solution to road transport is rail, when rail cannot even fulfil its potential market share. They weaken the real prospects for complementarity between the two modes. Indeed, when rail cannot handle traffic that is technically suitable for trains, it is difficult to see how a massive transfer between modes could be achieved. Even sharing future growth in traffic flows is utopian. Nevertheless, rail can be very useful, even indispensable, for rationalising the use of transport.