----The s-p-e-e-d of a train-----[ NSW]

[" Ian" <iansmith@optusnet.com.au>]

I wonder if some of the group can help me?
How is the speed of a train  determined ? I presume that the driver has some
instructions -signage etc.
I ask this question because , on a train from Seven Hills to Westmead, some
days ago,the speed seemed excessive, to the point it concerned quite a few
passengers. The whole set was bouncing around a fair bit and it was very
hard to stand.
A few comments to the guard at Westmead by some travelers,were just laughed
off.
Rgds...............................