Pete C. > wrote:

> The real question is why they don't have decent collision
> avoidance sensors up front. Granted on curving sections you
> won't get enough range to help much, but straight shots coming
> into stations they should be able to detect a stopped train /
> obstacle far enough ahead to auto apply brakes in time to if
> not completely avoid impact, do so at a greatly reduced speed.

Because technology cannot solve everything.

Look at Air France. The cause has not been determined
but it could likely be pilots unable to fight the computers'
behavior when various electronic systems fail. Systems
designed to avert accidents instead causing them.

S.