Look at this new signal: https://www.youtube.com/watch?v=IzmGNg7pBtM
Just a cheap setup not using controllers one would find in actual use for demo purposes.
Cool setup
https://www.youtube.com/watch?v=I2mvY1F3N4M
Quote from: Amtrakprod on September 23, 2019, 03:08:33 PM
I wonder why WSDOT had to re-invent the wheel? Other states use portable traffic signals for the same effect.
Quote from: TEG24601 on September 23, 2019, 05:50:33 PM
Quote from: Amtrakprod on September 23, 2019, 03:08:33 PM
I wonder why WSDOT had to re-invent the wheel? Other states use portable traffic signals for the same effect.
Seems like a steady red light should be used here instead of a flashing light. But I agree that temporary traffic signals would be even more appropriate.
flay-gger . . . hehehehe . . .
Quote from: DRMan on September 23, 2019, 07:23:43 PM
Quote from: TEG24601 on September 23, 2019, 05:50:33 PM
I wonder why WSDOT had to re-invent the wheel? Other states use portable traffic signals for the same effect.
Seems like a steady red light should be used here instead of a flashing light. But I agree that temporary traffic signals would be even more appropriate.
This device is what's mentioned in the MUTCD as a "STOP/SLOW Automated Flagger Assistance Device" (AFAD).
My thought is that a stop/slow AFAD is used in a situation where there is a one lane operation at day during work activities (like a minor resurfacing), but the road is returned to no restrictions after work hours. The setup seems to require a person to operate the sign, which, operationally, is no different than having the flagger standing there. In that case, this device is a quick setup for daytime work operations that is also easily removed by the flagger when work is done for the day. The MUTCD actually recommends the stop/slow AFAD not be used for long-term use.
In the case of major work (such as a major reconstruction), you would have a 24/7 lane closure. In that case, using the more complex setup of a traffic signal makes more sense.
As to the red light used on this device: In this context, a steady red light is not appropriate. The red light above is supplementing the stop sign, which makes it a beacon, and requires it to be a red flashing light when the stop sign is displayed.
Quote from: roadfro on September 24, 2019, 03:59:37 PM
The setup seems to require a person to operate the sign, which, operationally, is no different than having the flagger standing there.
About the only real difference is the flagger can be located far off the roadway, where it's safer. And maybe motorists respect a sign and gate more than a person.
Quote from: roadfro on September 24, 2019, 03:59:37 PM
As to the red light used on this device: In this context, a steady red light is not appropriate. The red light above is supplementing the stop sign, which makes it a beacon, and requires it to be a red flashing light when the stop sign is displayed.
In that case, I disagree with the MUTCD on this one because that stop sign isn't a normal stop sign. It's functionally equivalent to a red light on a temporary traffic signal, though I've never seen a temporary signal with a gate.
Quote from: roadfro on September 24, 2019, 03:59:37 PM
As to the red light used on this device: In this context, a steady red light is not appropriate. The red light above is supplementing the stop sign, which makes it a beacon, and requires it to be a red flashing light when the stop sign is displayed.
But the thing is its not really a real stop sign, as the normal stop sign rules, as you are allowed to proceed after stopping as long as nobody is making a conflicting movement. With this sign, it doesn't matter if nobody is in the way, you aren't allowed to proceed.
I do like that device, but it feels like it should have 2 red lights that wig wag, just like a railroad crossing. Infact, ideally, the HAWK signal setup could be used (and removed from HAWK use). This seems much more appropriate, no green light as its very temporary, yellow to alert you gate is about to go down, wig wagging reds to stop all traffic.
Quote from: jeffandnicole on September 24, 2019, 04:25:56 PM
Quote from: roadfro on September 24, 2019, 03:59:37 PM
The setup seems to require a person to operate the sign, which, operationally, is no different than having the flagger standing there.
About the only real difference is the flagger can be located far off the roadway, where it's safer. And maybe motorists respect a sign and gate more than a person.
Also, I'm not familiar with these devices, but it would seem like you could reduce down to a single flagger, located in the middle of the work area, with a much better view of whats going on, instead of having 2 or 3 people at the entry points to the work areas, so flagger labor costs should go down by at least 50%
Quote from: UCFKnights on September 25, 2019, 12:37:36 PM
Quote from: roadfro on September 24, 2019, 03:59:37 PM
As to the red light used on this device: In this context, a steady red light is not appropriate. The red light above is supplementing the stop sign, which makes it a beacon, and requires it to be a red flashing light when the stop sign is displayed.
But the thing is its not really a real stop sign, as the normal stop sign rules, as you are allowed to proceed after stopping as long as nobody is making a conflicting movement. With this sign, it doesn't matter if nobody is in the way, you aren't allowed to proceed.
I do like that device, but it feels like it should have 2 red lights that wig wag, just like a railroad crossing. Infact, ideally, the HAWK signal setup could be used (and removed from HAWK use). This seems much more appropriate, no green light as its very temporary, yellow to alert you gate is about to go down, wig wagging reds to stop all traffic.
It's just the same as if a flagger was holding the stop/slow paddle instead. You can't proceed until the flagger flips it to slow.
I do like the concept of using the HAWK-style beacons on this device, without a solid red period. Especially if the device has a gate arm.
Quote
Quote from: jeffandnicole on September 24, 2019, 04:25:56 PM
Quote from: roadfro on September 24, 2019, 03:59:37 PM
The setup seems to require a person to operate the sign, which, operationally, is no different than having the flagger standing there.
About the only real difference is the flagger can be located far off the roadway, where it's safer. And maybe motorists respect a sign and gate more than a person.
Also, I'm not familiar with these devices, but it would seem like you could reduce down to a single flagger, located in the middle of the work area, with a much better view of whats going on, instead of having 2 or 3 people at the entry points to the work areas, so flagger labor costs should go down by at least 50%
The MUTCD requires two flaggers to operate the AFADs in most cases. One flagger can operate both sides in cases where the flagger has unobstructed views of both AFADs and approaching traffic in both directions.
Or you can just use a standard RYG signal at either end and not have to worry about the MUTCD interpretation. Hell, even Oklahoma's figured this one out.
The video at the start of this thread would appear to be a version of the "driveway assistance device" currently under experimental use in multiple states. https://static.tti.tamu.edu/tti.tamu.edu/documents/0-6708-1.pdf (https://static.tti.tamu.edu/tti.tamu.edu/documents/0-6708-1.pdf) may be of interest.
Quote from: Scott5114 on October 02, 2019, 05:39:21 AM
Or you can just use a standard RYG signal at either end and not have to worry about the MUTCD interpretation. Hell, even Oklahoma's figured this one out.
That works for a 24/7 closure. But if it's a daytime only application, a signal is more complex than necessary.
Quote from: roadfro on October 04, 2019, 12:39:58 AM
Quote from: Scott5114 on October 02, 2019, 05:39:21 AM
Or you can just use a standard RYG signal at either end and not have to worry about the MUTCD interpretation. Hell, even Oklahoma's figured this one out.
That works for a 24/7 closure. But if it's a daytime only application, a signal is more complex than necessary.
Not really–you can just set the signal to be green on both ends when no work is being done.
Quote from: Scott5114 on October 02, 2019, 05:39:21 AM
Or you can just use a standard RYG signal at either end and not have to worry about the MUTCD interpretation. Hell, even Oklahoma's figured this one out.
That is not equivalent to this though. The flaggers are manually controlling the signs/gates to determine when they switch, instead of a simple timed (or sensor-based) cycle like for a temporary traffic signal. This is needed for situations where the construction may block all lanes for a time and "STOP" must be shown for both directions. I have seen WSDOT use signals in locations where they are appropriate, which would be where the construction is contained in a specific location and would never block the open lane.
Quote from: stevashe on October 05, 2019, 03:30:07 PM
That is not equivalent to this though. The flaggers are manually controlling the signs/gates to determine when they switch, instead of a simple timed (or sensor-based) cycle like for a temporary traffic signal. This is needed for situations where the construction may block all lanes for a time and "STOP" must be shown for both directions. I have seen WSDOT use signals in locations where they are appropriate, which would be where the construction is contained in a specific location and would never block the open lane.
We have the technology to set both temporary signals to red. This electronic flagger thing is needlessly complex.
Quote from: MNHighwayMan on October 05, 2019, 03:38:27 PM
We have the technology to set both temporary signals to red. This electronic flagger thing is needlessly complex.
The AFAD devices are appropriate to some applications, and temporary traffic signals appropriate to other applications.
If you're going to have a work zone closing the road down to one lane, and that closure is going to be during daytime 8-5 for five days, using an AFAD/flagger setup is much quicker and less complex than employing a temporary traffic signal. If that same closure is going to be for five weeks, it may be more beneficial and economical to use a temporary traffic signal than an AFAD/flagger setup.