Barling -
Happy to have an economic debate off-line but this probably isn't the place!
However, I do take issue with your view that the loco boom would have levelled-off in the mid-noughties. Even in recession, the major players have continued to add to their fleets. Without recession, the increase would have been greater. Think too of the depth of the recession in the eurozone and the effect that has had on the propensity to travel, yet still fleets have increased.