Traffic light experiment in Zelenograd, Russia

[WHBM]

Flashing green is in use in North America, certainly certain Canadian provinces and I think some US states, for protected left turn, where we would use a green arrow.

I also recall there from long ago a few junctions, probably after accident history, had advance warnings about 150m beforehand, where wig-wag yellow lights on high masts would flash just before, and when, the signal changed to red, with signage "Prepare to stop when lights flash". These even struck me at the time as encouraging flooring it to get through.

Long experience of signals in Los Angeles, which are typically simple two-stage cycles, with the requirement to give way to pedestrians when turning as they are given the "Walk" signal, is that the oblique view of the side street pedestrian signal, despite them being part-shielded, starting to flash "Don't Walk" gives an equal warning that your main signal is about to change.

[WhiteBlueRed]

I notice mention of them adding in an 'all red' at places where they've removed the flashing green. I get the impression then that it's normal to have no all red clearance period because of the flashing green. Is this a general rule (i.e. you never see an all red being used), and is the flashing green time adjusted to suit each junction, or is it always a fixed period of time?

It is normal (and actually the standard) for there to be no all-red period between stages. I only know of a few junctions (generally big ones) in my city where there is an all-red period, and they are more of an exception than the norm.
According to the GOST, an all-red period is only used when the "intermediate tact" exceeds 3 seconds. (so in this respect we have the same regulations). A major reason why it's like this, is because the way of calculating the "intermediate tact" is different here. If the UK and other countries consider the time it takes for a vehicle travelling from a stop line to reach the furthermost conflict point only as the all-red period of the intergreen, Russia on the other hand considers that as entirety of the "intermediate tact". Thus, the amber light acts as the first 3 seconds of the clearance period between stages.
According to the rules here, the amber light prohibits movement, unless you can't stop without resorting to emergency braking (rule 6.14).
A lot of drivers though think it's actually a "warning indication", and as such are not afraid of driving on amber. And the inaction of the traffic police further reinforces this behavior. This results in there being effectively no "clearance period" between stages.
Speaking of that, some cities with traffic enforcement cameras have recently started fining drivers for driving through an amber light. As expected, disgruntled drivers tried to dispute the fine, justifying their action by rule 6.14. But the courts no longer blindly accepted that excuse. The driver had to prove that he indeed had no other option but to drive through the amber light. And in most cases, the courts ruled that if there was a flashing green period (which there is at almost all signals), or a countdown timer, the driver should've adjusted his speed as per rule 10.1 (that requires drivers to adjust their speed to conditions) such that he would not end up driving through the amber light. (which in those cases is effectively an all-red period)
In Moscow on the other hand, they never went that far. Instead, from 2014, they've been adding an additional all-red period after the amber light at certain junctions.
As for flashing green durations, according to the GOST, if a flashing green period is provided, it must always be 3 seconds long, with a flash rate of 1 flash per second. (deviation by 10% either above or below the specified flash rate is permitted)
Although that generally is the case in practice, I've seen it flash for 4 seconds, and sometimes for 2.5 seconds (with all lights being off for half a second before changing to amber), at some sites. This might have something to do with the "flash rate deviation leeway" of 10%. Or it could simply be due to traffic engineers not following the GOST (which is not uncommon).

[freebrickproductions]

Flashing green is in use in North America, certainly certain Canadian provinces and I think some US states, for protected left turn, where we would use a green arrow.

I also recall there from long ago a few junctions, probably after accident history, had advance warnings about 150m beforehand, where wig-wag yellow lights on high masts would flash just before, and when, the signal changed to red, with signage "Prepare to stop when lights flash". These even struck me at the time as encouraging flooring it to get through.

Long experience of signals in Los Angeles, which are typically simple two-stage cycles, with the requirement to give way to pedestrians when turning as they are given the "Walk" signal, is that the oblique view of the side street pedestrian signal, despite them being part-shielded, starting to flash "Don't Walk" gives an equal warning that your main signal is about to change.

As I mentioned earlier in the thread, the US MUTCD specifically bans flashing green indications on traffic signals in the United States, especially if to try and give an indication the light is about to change to yellow. Massachusetts did once use it for their signalized mid-block pedestrian crossings though, and I believe one of those still hides-out somewhere in that state.

Canada does use the flashing green in some provinces though for the protected turn, but it was also a fast flashing green for that. IIRC, Ontario was one, but they are slowly phasing it out. I believe Montreal was another?
Over in British Columbia, as I understand it, they use a much more normal speed for their flashing green indications, which are used at mid-block pedestrian crossings.

[KeithW]

Interesting to see that Russia is considering dropping the flashing green period.

I think the only place I've witnessed that in action was in Austria, and not from a driver's perspective. I seem to remember it looking strange (of course), but the way drivers appeared to react being no different to elsewhere without the flashing green, still amber gambling a lot of the time (as you'd perhaps expect given the impending change was clear). Mind you, that was in cities, and people do tend to drive differently in cities anyway so my observations might be slightly skewed!

I notice mention of them adding in an 'all red' at places where they've removed the flashing green. I get the impression then that it's normal to have no all red clearance period because of the flashing green. Is this a general rule (i.e. you never see an all red being used), and is the flashing green time adjusted to suit each junction, or is it always a fixed period of time?

I have see flashing green on US roads that are not freeways essentially warning you to prepare to stop and others that outside the busy periods just display flashing amber to all aspects, this one on Sinclair Road comes to mind.
https://www.google.com/maps/@40.0707009 ... &entry=ttu

I used to drive along it as there was and still is an International Grocery Store there that sold Asian foods, proper marbled meat , mangos and lamb which can be hard to find in Ohio. The Apartment block where I lived had a lot of Japanese expats working for Honda and they put me on to it. Who knew that schweppes bitter lemon and ginger beer were classed as ethnic drinks or that Lyles Treacle was an ethnic food

[WhiteBlueRed]

Over a month has passed since I posted this. More information and opinions on this change is now available. I'll summarize several news articles into one post.
Shortly after the change, disgruntled drivers have started a petition to bring flashing green back on Change.org. It has already been signed by over 6000 people.
Some time later, the experiment was expanded to all intersections in Zelenograd. The MTOC have clarified that this is not actually an experiment, but rather a change made to improve road traffic safety.
The traffic police in Zelenograd had recently spoken out against the change, stating that crashes at intersections without flashing green have actually increased, and that information about "mass acceleration" on flashing green is not true. According to them, the total amount of RTAs from October 1st to October 26th has increased by 29% compared with a similar period last year. The amount of collisions has increased by 42%, and the amount of crashes directly related to traffic at intersections has increased by 62%.
Urbanist bloggers have stated that the information provided by the traffic police is misleading. The only crashes the police counts are those with casualties, excluding those where only vehicles were damaged. There are 5 districts in Zelenograd, in 2 of which there were no crashes at all. In other districts, there were 12 crashes, 1 death, and 13 injuries. None of them were related to the experiment, and 9 crashes happened far from any traffic lights.
The MTOC stated that this change will last until at least the end of November.
Lastly, another city decided to conduct this change too, for the same reasons. Traffic lights at 3 intersections in the city of Vladivostok no longer flash green.