Arkroyal,
Shortly after the Selby crash, there was an article in a railway magazine querying the safety of push-pull trains. There was a nasty accident in Scotland in the 70's because of the leading vehicle (driving trailer) being too light when a cow was hit. Had the train at Selby been a conventional loco hauled trained with a 90 ton loco as the leading vehicle, there's an arguable chance that fewer people - if any - would have died. As you say, vehicles shouldn't (especially relatively small light vehicles) be able to fall on a line and cause a disaster. The fact that it can happen demands a scape goat. Push-pull operation is a lot cheaper, though.
[ 17 December 2001: Message edited by: radeng ]