Re: Crossing loop design (r.e. Southern Aurora crash)

["Reuben Farrelly" <reuben@mira.AA.net>]

Hi Krel,

Krel <krel4203@netconnect.com.au> wrote in message
36c3474b.1609166@news.netconnect.com.au">news:36c3474b.1609166@news.netconnect.com.au...

>In Victoria this is called three aspect signalling. There are two
>lights that can show up to seven combinations:-
>G/R - clear normal speed "Top Green" in driver speak.
>Y/R - normal speed warning "Top Yellow"
>R/R - stop "On the red"
>R/Y - medium speed warning "Bottom Yellow"
>R/G - clear medium speed "Bottom Green"
>Y/G - reduce to medium speed "Reduce"
>G/Y - clear on a repeating signal (a repeater in Vic is like a
>distant).

This is probably going to seem like a pretty dumb question, but this system
as outlined above seems very un-intuitive.  Do you guys have to learn this
off by heart, or is there some logical rule which explains how things work?
Like, do you see R/Y and just "know" the indication, or can you apply some
sort of "formulae" to work out what it means?

>At some locations only one light is used. This is called two position
>signalling. The aspects are
>G - clear
>R - stop
>In 2 pos areas signal that have no stop indications are called
>distants (cf repeaters in 3 pos). These show only:-
>G - clear
>Y - caution
>Only distants can show caution, all other yellow lights indicate
>'warning' (no one seems to know why)

Those ones make sense though ;)

Reuben