[girishv]

VAC (Vehicle Actuated Control) is introduced in Bengaluru from couple of weeks. Initially many did not even know what exactly it is.

Before VAC, most of our signals had count-down timer and I always used to turn-off the engine when the time left was more than 20 seconds. With VAC, we no more have that option and the time for the signal dynamically changes depending on the vehicles waiting at the signal.

This seems like a good idea, but can be potential dangerous too. I drop my daughter to her tuition early morning around 5:30 when the traffic is almost zero. I have to take a right at one of the main roads as shown in the figure. The starting of the red line marks the signal where I stop before taking the right.

Last week, the signal turned green for me (both straight and right) and when I was at the mid of the road (marked with X), the vehicles from the opposite side started moving and I almost got hit by a two wheeler. I was very angry and shouted at him what is he doing. To my surprise he pointed front and said something about signal. Since it was only few seconds from the signal turning green for me, I thought he may be pointing at something else and just left the place.

Today I deliberately kept looking at the lights and to my horror, the right one became red within few seconds of turning green. Its not even possible to reach the place where I can start right turn in that time. And note that, there is no YELLOW between any of these changes.



Funnily, the VAC is of not much use during the day time also as I was forced to wait for around 5 mins on one particular occasion where the typical wait times earlier were less than two minutes.

Not sure how this is VAC is going to be with time :(

[mpksuhas]

One issue I have noticed with these VAC signals is that it goes to MNL mode and then will be green only for one road and the lights doesn't change.

I guess MNL means Manual and the change has to be done manually by the policemen manning the junction. However, twice when I noticed this issue was during early morning / late in night when there are no policeman at the signal.
I doubt maybe after some power disruption or something similar, the signal is switching to MNL causing this.

At first this was on airport road at Windsor junction. There was a pile up of vehicles towards airport due to this, however cabbies were honking and jumping the signal from start, guess they are aware of this issue. I was there for some 5 mins in that traffic, all while no change in the lights. This was around 4.00 AM on a Saturday.

Second instance was at BTM - Udupi garden signal, again a Saturday, may be around 5.00 AM, same issue with one side green for long, all other roads long line of honking vehicles.

For those who are wondering what VAC is , you can check out here (Bangalore gets AI-powered adaptive traffic control system to ease congestion)

[Avikbrio]

This absolutely falls in line with the other issues that go on in Bangalore. There is no follow up or checking to see if the system is working as expected. It will not be long and you will see all signals will go into MNL mode or simply stop working.

The best thing one can do now is take pics/videos and complain on twitter tagging the respective authorities. Also open a complaint with BTP.

[Rajeevraj]

I have noticed that these kind of projects seem to be taking off and expanding very quickly. The VAC based signals were piloted for a couple of months, declared to be a success and then rapidly rolled out. I think most signals in the core areas of Bangalore have been upgraded and it is making its way to areas in East Bengaluru. I had read an article regarding some of these issues. Especially the no orange issue and the Traffic Commissioner had said they were fixing it. Looks like we need to bear the brunt of the experimentation.

[kadanaJ]

As usual with our government, these systems will undergo a lot of failures initially, and the common people will face a lot of hardship until the authorities figure things out.

This is a system that is great in theory, and has the potential to improve things massively, but that will take time.

The best thing that members from Bangalore can do, at least those who have dashcams, is record faults with the system and forward those videos to the relevant authorities.

It may take them months to incorporate feedback and improve the system, but in the long run there is a lot of benefit to be gained from these automated signals over the old fashioned timer ones.

[MDED]

I’m a big fan of VAC signals, however it works best at heavily congested junctions where they have set up separate traffic cams to gauge the flow of vehicle on either side. For e.g. Koramangala St John’s junction. They have installed additional cameras at least 50 meters from the traffic junction to gauge the movement.

The speed at major chocked junctions have gone up, for e.g at Double Road Shanthi Nagar bus depo junction has become easy now. Earlier it was pure pain to cross in the mornings. At many sections wherever cops change it to MNL mode, then the issue creeps in, as AI goes to the drain!

[wheelspinner]

They should tune the signals properly so it can create a safe buffer for periods of low congestion. How does it internally work? Does it use some algorithm? Sounds like a software issue that they should work on resolving.

[W.A.G.7]

Why complicate life unnecessarily? I mean let’s just use our signals as they did during the good old days! I hate these kind of advancements. For these to work correctly, the implementation has to be flawless, which I realise is going to be next to impossible in our country. The problem is not with these type of signals. The main problem is the huge volume of vehicles on the roads in our country, which no computer can solve without human interaction at some point of time. Maybe are we trying to solve the wrong problem and the actual problem lies somewhere else?

Let’s just uncomplicate our lives!

[audioholic]

One trick to guess when the signal will turn green is to keep an eye on the status indicator. When the signal is red, it switches from VAC > Wait > Stop > Go. Thats when it turns green. I follow this pattern to know when to slightly reduce pressure on the brakes so that the car starts. After that, a second later I get to roll off. I think these days I havent faced issues with the VAC signals. There are two signal systems now operating in Bengaluru. The CBD has a Japanese system with much more advanced traffic monitoring and lane level tracking with integration of multiple signals. The other one is the signal with the VAC displays which have been installed in many junctions. The former works pretty well, and the latter is prone to timing issues.

[dileepcm]

Originally Posted by girishv

VAC (Vehicle Actuated Control) is introduced in Bengaluru from couple of weeks.

the vehicles from the opposite side started moving ...(

These systems need very good level of tuning. I really hope they invest time and money in getting it tuned as otherwise these systems can really be dangerous as you have experienced.

I think whoever is in charge should collaborate with the responsible folks here in Netherlands, which has some of the best quality and most sophisticated traffic management systems.
Even cycle lanes have its own detection and management systems.

Worth a watch:

https://youtu.be/knbVWXzL4-4?si=LCkZ-s1pBvm4-FHJ

[RevvedUpInsider]

I read/heard somewhere that countdown timers will be introduced in the near future for these VAC signals. The company building it is Arcadis, and they said that in the future they will also integrate signals at multiple junctions. These signals will communicate and try to turn green in a synchronous manner in cases like Outer Ring Road, Banashankari where there are multiple traffic junctions in the same straight path, the signals will be linked to each other to reduce waiting time by turning green by the time you arrive at the next junction. It will be much harder to implement it successfully but still exciting times and I think it's a move in the right direction!

[PreludeSH]

There is nothing inherently wrong with the technology. Its only about the implementation that is lacking. The people giving the inputs should be smart to make it work right.

I welcome this initiative and you can have a network of these over 5G and make it work seamlessly towards minimizing waiting times at signals.

[condor]

With the current levels of traffic, I dont see much of a difference when VAC is working. Manual is as always, at the mercy of the cop manning the signal.

But what I miss is the count-down timer. I wish they bring it back.

[ajmat]

It has the potential to work but what works against it are:

Junctions - People do not keep junctions clear. They ideally should not enter a junction until it is totally clear but all of us are guilty of cheating the orange light or not in a position to halt due to the hustling from the cars behind

Lane Discipline - Quite clear on the Old Madras Road. The straight ahead lane is constantly blocked by people wishing to turn right. This misleads the systems.