Advance warning flasher

[Mike]

Hi Greg,

Advance warning flashers (AWF) are used in BC quite often to inform drivers when a signal is about to turn red. They look like so:
http://www.richmond.ca/__shared/assets/ ... op9567.jpg

Lets say that Phase 2 has a AWF on its approach.
The way a a traffic controller is programmed out in the field is that the Phase 2 YELLOW and RED outputs drive the flash relay forcing the AWF to start flashing. The signal head is driven by a Lagging Overlap A (Lag Overlap A's parent phase is phase 2). The lag time determines the delay time from when the AWF starts flashing to the time the actual signal head (driven by the overlap) turns yellow.

In Tru Traffic, when coordinating a signal with an AWF, I have to manually subtract the lag time of the overlap from the Offset given to me from Tru traffic to guarantee proper coordination out in the filed. (My offset is the Start of Yellow - I did not choose this, that's what the client wants).This would not be an issue if the reference point was Start of Green.

It would be nice if Tru-Traffic had an option to take this into consideration for the approaches. Not a big issue, just a thought.

Mike
DMD & Associates Ltd.

[bullock]

Thank you for the great suggestion, Mike. It's now on the to-do list.

I hope to be able to slip it into a minor update soon, but if not, then definitely in the next major version upgrade.

If I understand correctly, then to do it properly, it seems the software must allow the user to not only enter the AWF lag time, but also to set the offset reference point to start of AWF (instead of start of yellow). Correct?

Regards.
Greg

[Mike]

Actually Start of Yellow is correct, because that is the actual reference point that the controllers (Econolite-ASC3 and ASC2's) are programmed for. It's just that if I program a reference offset of 20 seconds, the actual Start of Yellow in the controller will occur at 20 seconds, however physically out in the field this is the time the AWF start flashing, then (whatever the lag overlap time is, lets say 5 seconds in this case) 5 seconds later the light goes yellow, giving a visual appearance of a 25 second offset.

I don't think we need to change the offset reference point, I'd keep it as is.

Maybe just something as simple as checking off a "Advance Warning Sign Present" checkbox for that phase at that intersection, and then an astrix beside the 20s offset, just as a reminder that that's not the actual offset to enter into the coordination settings in the controller.

or

Maybe field somewhere where we can subtract the 5 seconds from the offset given by Tru-traffic. That's all, so when I get the printout from Tru traffic it would say (20s - 5s) = 15sec offset, beginning at the start of yellow.

I'd go with the 1st since it's simple.

What do you think?

[bullock]

Thank you for educating me on this, Mike. I appreciate your detailed descriptions.

I'd go with the 1st since it's simple.

What do you think?

I'm happy to go with whichever is simplest and clearest to you (the user) without regard to which is simpler for the developer. That is, I'd like to implement the one you'd most like to see. Is that what you mean in recommending the 1st option, that it's the simpler option for the user?

Regards.
Greg