I got to see Montréal's way of displaying an LPI (or LTI, Leading Thru Interval) when I went to Montréal two weeks ago in person and it reminded me of another signal sequence that is very similar around the Los Angeles area for LTIs.
This is for a permissive and/or permissive/protected setup. For the LTI:
- In Montreal, the signal starts with a upward-facing green arrow when "WALK" is displayed. It changes to a circular green after the LTI ends. There is a 5 and 6-section version of this signal, with the indications being (R-Y-G-UfGA-LtYA-LtFGA). LtYA is omitted in the 5 section version and it also could have a transit bypass signal as well on the top instead of LFGA. The ones with left turn phasing were all lagging left.
- In Los Angeles (circular red-red arrow signal), the signal starts with both a red arrow AND circular green when "WALK" is displayed. It changes to a circular green after the LTI ends. (The LA setup shown here was changed to a fully protected setup with seperate signals)
Obviously, having separate signals (and dedicated turn lanes) for each movement with FYA works a lot better for signalling this operation. Besides this, I'm curious to see which one is better for signalling this operation: Montréal or Los Angeles?
The LA one has something the Montreal one lacks--an explicit indication against left turns while straight is allowed. Something about the straight green arrow but nothing at all about lefts makes me worry that people might think either the signal is "broken" and lefts are allowed but dark, or that there is no signal phase at all relating to left turns (go whenever). The red arrow seems good to say "we didn't forget left turns--don't do it right now."
I agree. From a US perspective, we prefer to see a NO indication as opposed to understanding that a straight arrow implies no turns. In the US, the Montreal signal is a no-go. I don't know how the Montreal signal is interpreted in Canada. It seems that Quebec allows for right on red, except on the island of Montreal.
And it seems like its common there.
Take a look at this sign.
https://www.google.com/maps/@45.5785795,-73.5600436,3a,75y,224.68h,98.99t/data=!3m6!1e1!3m4!1sJboCjJvi8r4o3peU5iRFCg!2e0!7i16384!8i8192?hl=en&entry=ttu
It is striaght and right in a green circle. Can you turn left here? Since only straight and right are in the green circle, left turns are prohibited. In the US, the would have a no left turn sign instead.
- In Los Angeles (circular red-red arrow signal), the signal starts with both a red arrow AND circular green when "WALK" is displayed. It changes to a circular green after the LTI ends. (The LA setup shown here was changed to a fully protected setup with seperate signals)
That setup is identical to this current LPI in Spokane, WA. Red arrow at the beginning during the LPI, before being extinguished and only a green orb is displayed.
Unfortunately, I cannot find a GSV showing a green orb + red arrow. And, investigating GSV for a bit, there is some evidence that the LPI may not always be active: these cars are setting off at a freshly green light, but there is only green orbs, and the "Don't Walk" sign is displayed.
And that is a good thing. As there are pedestrian activation buttons, the LPI should only be operational when the WALK signal is operational. If no pedestrian pushes the button, there is no need for an LPI.
