[D4D]

Originally Posted by msdivy

It is a nice idea. It was discussed in WP...

Actually UPS drivers avoid left turns (LHD) where ever possible. Since right lane turn right is strictly enforced, travel time is reduced if you take series of free right turns.

Thanks for the Info! These are examples to prove that it can be done.

Originally Posted by SS-Traveller

Certainly needs excellent lane discipline to implement it. Can't say that exists in this country.

Originally Posted by condor

For India, a far simpler approach of crossing the line only if they can cross the intersection before the light turns red can make a big difference.

That is going to take hell lot of time and effort to drill some common sense into some haybrained drivers.

Originally Posted by joybhowmik

Ithe concept of yielding to someone is unknown

I have to regretfully say that I belong to the second category when the traffic is behind me. Sometimes, I take a narrow inclined road. When I go downward, I always want to stop and give way to the person coming uphill. But on many instances, people behind me honk so much it nearly blasts my eardrums. A guy swore at me for stopping and allowing a car to come up.

Sorry for going OT.

[fine69]

I don't think this concept is as much practical as it looks. I mean if one has to take a u-turn only to be the 4th or 8th car from the red light then why would one have 60 second green light on that signal.

8-10 rows of cars can pass within 30 seconds so why have longer wait times. However, if the traffic is dense then as such one cannot take a u-turn to be in the 8th row. The extra travel time along with the delay in taking the u-turn while the other signal turns green and there's another bottleneck at the u-turn doesn't make this design too promising, at least to me.

[phamilyman]

This just won't work in India except in a few main roads with low traffic. As many outlined, the issues are many:
a. Not enough lanes to do so in most cities / no lane enforcement.
- We have such U turns on the MG Road in Delhi. Only in low/medium density areas (Saket) does it work, not in places like khanpur on the same road.
- In others, you will have 4 lanes fighting to get into the two lanes at the U turn - the exit from the U turn is not protected at times. (anyone in gurgaon remember the peak hour jams at the Rajeev Chowk on NH8 / Gurgaon expressway?)
b. Buses / autos stop at the damned intersection, and not 100m ahead. Is it a surprise jams occur?
c. Idiot bikers will drive 100m wrong side but not ride 200m to the U turn.
d. People don't respect the intersection as written earlier. There has to be zero tolerance on this subject.
e. Put all of the above and then our zero enforcement. We need Chennai like enforcement where they don't shy away from challaning folks right there.

If they are interested, they make it work. That's the big issue - no appetite for real enforcement. Instead of flowing water, what we end up with a whirlpool going round and round, more like a cess pool!
Anyone who was in Delhi during the CWG knows how well the same infrastructure coped with the CWG lanes blocked off!

[fine69]

Originally Posted by phamilyman

Anyone who was in Delhi during the CWG knows how well the same infrastructure coped with the CWG lanes blocked off!

I remember hundreds of policemen/home guards standing every 50-100 meters just to stop vehicles from entering the CWG lane.

I mean if with "cops" standing on the road they couldn't prevent vehicles from entering the CWG lane how can something like this work on regular days.

Dream on!

[joybhowmik]

Originally Posted by fine69

I don't think this concept is as much practical as it looks. I mean if one has to take a u-turn only to be the 4th or 8th car from the red light then why would one have 60 second green light on that signal.

8-10 rows of cars can pass within 30 seconds so why have longer wait times. However, if the traffic is dense then as such one cannot take a u-turn to be in the 8th row. The extra travel time along with the delay in taking the u-turn while the other signal turns green and there's another bottleneck at the u-turn doesn't make this design too promising, at least to me.

And so the thread veers into territory of vehicle density per sq.m. I agree.

When a city has dense traffic (especially at certain times of the day), C's can be more a problem than a boon.

But then that's in the realm of urban planning (roads). Why? Chokes happen on Indian roads due to their varying width. These chokes, almost always back up to the slowest moving lane - i.e the C / U turn, and spread like wildfire to the rest of the lanes.

So, it all goes back to the basics. Reduce vehicular density. More public transport/less private transport. Or find a way to increase road width.

[fine69]

Originally Posted by joybhowmik

So, it all goes back to the basics. Reduce vehicular density. More public transport/less private transport. Or find a way to increase road width.

Which brings me to the other part of the argument. Would one really save significant time if there were fewer vehicles on the road to begin with.

Also, is it better to stop at a signal for 60-90 seconds than take a left, make a u-turn and spend 20-30 seconds doing that eventually saving only 40-60 seconds.

I agree that over 10 signals I might end up saving 5 minutes but that when I'm assuming all lights will always be green, no stopping time after taking a u-turn and there are no other variables in play.

We talk about lane discipline with the 'GreenLight' concept but what we fail to understand is that if lane discipline is followed on a red light we'd see far more cars crossing an intersection in 90 seconds compared to when there are 3-4 lanes made by vehicles on a two-laned road.

Whenever we are waiting for the train to pass on a railway crossing there's always that bunch of morons who come and stop bang opposite to you on the other side. While a few of those morons obviously pass a whole lot sooner than the others but it takes 2-3 times more to cross that crossing compared to what it would take if everybody simply stood by their lane.

I strongly feel that the video has exaggerated the time saving here.

[phamilyman]

Originally Posted by fine69

I remember hundreds of policemen/home guards standing every 50-100 meters just to stop vehicles from entering the CWG lane.

I mean if with "cops" standing on the road they couldn't prevent vehicles from entering the CWG lane how can something like this work on regular days.

Dream on!

Disagree man - maybe we just had different experiences during the CWG. I commuted daily from Gurgaon to Vasant Kunj area, and had around 4-5 morning meetings in CP at that time. On the average I distinctly remember taking the same time or being a bit faster. Even my brother commuting on MG Road from south delhi to gurgaon reported things being normal.

Secondly my current enforcement expectation is how chennai runs. Leaving aside the fact that they give free reign to MTC buses and kamikaze bikers, they strictly enforce car traffic and during peak hours they keep it moving as nicely as a good traffic light (unlike most delhi traffic policemen). Further their strict challaning for every little reason, ensures that no one does anything remotely stupid (including getting challaned for parking on an arterial road within 2 minutes, even though traffic was non-peak and not obstructed).

[joybhowmik]

Originally Posted by fine69

Whenever we are waiting for the train to pass on a railway crossing there's always that bunch of morons who come and stop bang opposite to you on the other side. While a few of those morons obviously pass a whole lot sooner than the others but it takes 2-3 times more to cross that crossing compared to what it would take if everybody simply stood by their lane.

Can't help but respond to this rather obliquely.
The Indian human genome has at least 1 common gene with the Indian crab.
So, when the Indian man faces the same way as his brethren, he always tries to out-do them - just like the lowly crab. Nope , he does not have a medical emergency, he does not even have to visit the bathroom urgently - it's just in the genes!
Did not mean to be sarcastic - but I guess I am preaching to the choir!

[srishiva]

In New Jersey U.S, they have something called Jug handle turns. Basically for us, if you have to take a right turn, you go straight, cross the intersection and take sort of a exit towards your left and join the traffic that would go straight. You need some space though but it will take care of dense traffic situations since you can wait on the exit itself for some time.

In our case for greenlight, there is so much traffic that the vehicles would block the road unable to take a complete U turn.

[khoj]

So, you are back

Originally Posted by joybhowmik

Did not mean to be sarcastic - but I guess I am preaching to the choir!

In the scenario below, as it is described one can never complete that right turn which in any case is a free turn state side. What is amiss?

Originally Posted by srishiva

In New Jersey U.S, they have something called Jug handle turns. Basically for us, if you have to take a right turn, you go straight, cross the intersection and take sort of a exit towards your left and join the traffic that would go straight. You need some space though but it will take care of dense traffic situations since you can wait on the exit itself for some time.

In our case for greenlight, there is so much traffic that the vehicles would block the road unable to take a complete U turn.

[narayans80]

There are quite a few assumptions that are made in this video.

- All intersections are 4 way and have at least 2 lanes on either side of the divider. While the first case could be found, having 2 lanes for each side is a rare sight.
- Signal duration of 1 minute for both N-S and E-W roads assumes that the traffic density on each direction is the same. However in reality the green time is proportional to the traffic density at a given time of a day for that direction in that intersection.
- For the jug handle type of right turn to work. You have to dedicate the right lane for that distance to let the vehicles merge in. Also if there are lot of vehicles that make a right turn, how long should the lane be? It'll also be difficult for large vehicles to do U-turns.
- The video also assumes that there are no pedestrians. There are quite a few traffic lights in my commute route alone that go red to let pedestrians cross the road. Anna University entrance on Sardar Patel Road and Saidapet Market traffic lights on Mount Road are 2 examples I can think of.

If the straight heading traffic forms the majority, giving a green to drive straight for both sides opposing traffic is already in action many intersections. A small percentage of time is left for the right and U turn taking folk.

[Technocrat]

Originally Posted by SS-Traveller

Not a ground-breaking idea. Look up hook turns - a common feature in Melbourne. http://en.wikipedia.org/wiki/Hook_turn

Certainly needs excellent lane discipline to implement it. Can't say that exists in this country.

There is a slightly different but more practical design called Jughandle Turns which can be seen in some US states like NJ

But its mostly implemented on highways or major roads which pass through the city. since this does not involve yielding, this might work. The only problem that i can see is that due to high volumes in India they would probably have to make it a long one. Besides lack of lane discipline will still make it harder to deliver the intended results.

[ambivalent_98]

A novel idea but the "C" turn can have cars , buses and two lanes trying the "C" turn in parallel which complicates things when they are not. You need to nip the problem in the bud by providing a mix of flyovers perhaps at junctions where heavy traffic crosses. Apart from that another high probability of slow traffic is bad roads. People slow down since they cannot dodge the craters on the road. They navigate those but at almost 1/4th of the speed they would pass by that stretch. Imagine this effect multiplying 10 times when there are 10 times as many vehicles slowing down.
So IMHO , a C turn will work only when effectively implemented. Flyovers and underpasses and good roads might be the way forward.

[Sridhar K]

Have seen this implemented at two places in Chennai with mixed results.
a) OMR- Sholinganallur intersection - Partial implementation. What they have tried is to eliminate a right turn from an minor road onto a major road. Has reduced the wait time at the signal for folks driving on the major road by a great deal. They have also eliminated traffic on the minor road from passing straight through across the major road.

b) Exiting DLF onto Mount - Ponnamalle road. This plan has been dropped during peak hours as the the volume of traffic exiting DLF is very high and it causes traffic jams on the left turn at DLF exit and at the subsequent U turn.

The idea is a good one but one needs to look into the following factors before implementing.
a) Pedestrian crossings (volume of pedestrians)
b) Position of bus stops if any
c) Volume of traffic on the intersecting roads
d) Lane disciple
e) Traffic enforcement

In Chennai, the enforcement is very good for cars but pathetic for motorbikes, autos, share autos, MTC buses and police vehicles.

[srishiva]

Originally Posted by khoj

So, you are back




In the scenario below, as it is described one can never complete that right turn which in any case is a free turn state side. What is amiss?

I have changed the directions for our traffic i.e for driving on left side.

Some bikers already do this at silk board junction. They push their bikes and join the intersecting road on the right side so that they can take a right turn earlier instead of waiting for their turn !

Our volume is too much to support this kind of turns. We will block the wrong side lanes on the perpendicular roads and create a mess.