Re: Simple Question.....

[billbolton@REMOVE-TO-EMAILacslink.net.au (Bill Bolton)]

"David Proctor" <daproc@bigfoot.com> wrote:

> which will be preceded by a Green over Yellow,  which will be preceded by a
> Green over Green - thus, a driver will get at least two signals advance
> warning of a signal being at stop.

There are many signals in the Sydney suburban area with no yellow
light on the bottom head, so a driver may only get a one signal
advance warning of a double red.  The provision of a yellow light on
the bottom head (when no turnouts are involved) appears to be related
to traffic density and block length.

Cheers,

Bill

Bill Bolton
Sydney, Australia