Not sure if they still allow it, but I would suggest that you pop to the National Tramway Museum in Crich. I know when I was there a few years ago, I was able to arrange driving of a tram without any passengers. If they still do that, I suggest you have a lesson in driving a tram.
Then you will realise, what I say about drivers needing to have their full attention when driving a tram and if there has been two previous incidents, as seem to be the case where trams went round the corner at too fast a speed you would realise that you cannot control a tram to slow down as quick as you would a car that would be going round a similar type of bend.
I know what it takes to drive a tram. I do it every day, I also teach people to drive them so I dare say I know a bit more about it than you do.
Yes it does take longer for a tram to slow down than a car, that is obvious. The drivers route knowledge tells him the curve is there, it's not as if he is coming up to it completely unaware, as may be the case with a car driver.
As such, the driver should begin to slow down at a point which he knows he can safely and comfortably reduce to the new speed limit.
It doesn't matter what the speed limit prior to the curve is, nor does it matter how tight the curve is or whether there are sufficient warning boards. The curve is perfectly safe if driven appropriately. What matters is
why the driver, in this case, appears to have lost concentration to a degree that a horrendous incident has occurred.