The indicator can't illustrate what aspect the signal is displaying - only that it's showing a proceed. Therefore, it would be useless to a driver as he/she needs to know what aspect it is displaying (G, YY, Y).
There are two points to this statement. Firstly there is the logical inference that a driver can make from the OFF indicator, and secondly there is the actual operating procedures themselves.
Let's start with the sentence "Therefore it would be useless to a driver...as he/she needs to know what aspect it is displaying". Well that's clearly wrong.
Using clear logic one can determine that if the aspect of a signal is one of (G,Y,YY and not R), then the driver can proceed through the next section "as though" the signal were YY, and no faster.
So to say that the OFF indicator is *USELESS TO A DRIVER* is to simply ignore logic, and moreover after listening to some of the posters here - it is also to ignore FACTS.
I don't often post here, but I found the tone of Ralph quite out of place. Firstly he was quick to rubbish the claims of Strange6, but not only that, he did so when he had no actual knowledge of the working procedures in place.
I then found it interesting that Ralph started using this "mixed wires" metaphor. Let us speak the truth between us.
Strange6 made a reasonable conclusion.
Ralph with no actual knowledge or experience of these matters jumps in not once, but twice to tell Strange6 he is wrong.
Fortunately a more knowledgeable poster comes along and puts the record straight.
My whole point is that many people come here out of interest and curiosity, to learn more about the railways. How can it help when people who know "jack-sh*t" about anything start jumping down peoples throats to give their bit of wisdom that turns out to be incorrect ?
Wittgenstein said "what can be said should be said clearly, and what we cannot talk about must be passed over in silence", which was a kind of polite way of saying "if you don't know something then stfu".