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Going over Cauvery Junction Underpass
tsubba - 28 January, 2008 | Traffic | Bangalore | Infrastructure | magic boxes
Back-of-the-envelope analysis and some rough sketches to understand the
cauvery junction underpass solution. Looks like the palike will need
more than the magic of precast boxes to make this work.
Existing situation
The image to the right shows the the existing situation at the
junction. Vehicles going south to north and north to south travel
straight along the bellary road. Vehicles from south going to the west
take left on the slip road. Vehicles from west going north from west
take left on the slip road.
The main conflict is between
north-south traffic and vehicles from the west going south towards the
city. When vehicles from west heading south towards the
city crosses the road, both north bound and south bound traffic has to
stop.
The palace maidan is to the right of bellary road. 1st main and 18th
cross are two other roads in the area. Both sides of
sankey road and the western side of bellary road are lined with
business.
Ideal solution
If some space to the east of bellary road, on palace maidan was available, then true signal-free fast movement through this junction would have been possible. One such ideal solution is shown in the figure to the right. Simply lift the problematic linkage and ease it into the south bound traffic. The main linkage now has to only deal with merging and exiting traffic.
Other variations to the theme, like underpass or a loop that bends backwards etc are also possible. But as idontspam has pointed out acquiring palace lands is not possible.
Thus, it is not possible to separate the problematic west-south linkage by physically moving it.
An idealized alternative
One way out is to move the main link iself and that is what, I think, the palike is trying to do. An idealized version of this solution is shown to the right. It is not so much a U-turn as it is going through a circle or roundabout - only, in this half circle, there is traffic at the center of the circle instead of somebody's statue.
South bound traffic still has stop to let traffic from west going south, to cross the bellary road. S1 and S2 will be two signals regulating usage of the road. When S1 is green S2 is red and vice-versa.
The bottomline of this design is that the north bound traffic(towards airport) gets continuos free movement by passing over all cross-traffic.
Actual implementation
But the success of this alternative rests entirely on the geometry of the actual implementation.
From what I have read on this underpass so far, all traffic headed to hebbal has to take this loop. Providing a nice little loop for single lane is fine, but for the entire throughfare on this road to take the loop, the loop better be wide with a nice and smooth curvature. If the turn radius is too small or the bend too sharp, then this design will seriously slow down north bound traffic. Hopefully the palike has paid enough attention to it.
Further, since actual turning on the loop happens on the underpass the question is, is the underpass long enough to ensure smooth u-turns? Also, is there enough space on sankey road to allow smooth u-turns? As is the norm for palike, no details were avaialable on the its website. And as is the norm for papers, no useful information was available in most of their reports either. But a report I read in the Hindu, fleetingly mentioned that the vehicles are to take the u-turn after travelling 50 meters on Sankey road. Based on that, I drew a rough approximation of a possible design. The red rectangles are approximately of the same size as the buses seen near the top right of the image. I dunno if the acual palike design is similar to this, but this figure highlights the challenges at Cauvery Junction.
The issue here is that deeper the loop goes into sankey road, away from bellary road, more difficult the turn becomes. On the other hand, if the loop is too close to the bellary road, then there will be no place for underpass traffic to emerge. As you can see the loop is real tight and traffic will have to slow down. That is OK as long as it keeps moving.
If the loop gets too tight, one alternative is to use this loop as a slip lane for north bound vehicles. When S2(see pic above) is green, they could make S1 and S3 red. Vehicles at S3 then have the option of taking the loop to avoid waiting for S2 to go red. When S2 is red, they just continue straight. That way, irrespective of the signal, vehicles at S3 always have an option to keep moving. Though all this switching could get messy and very confusing.
The palike will have to walk on a very tight rope to balance all this. It will be very difficult to make all this work. And I have not even said anything about the width of the underpass to carry all traffic from west headed to either north or south.
COMMENTS
I'm not confident
sidhanth - 9 February, 2008 - 21:45
You guys have done a great job on debating and reconstructing the junction and proposing ideas. However without wanting to be too negative, I think we are overestimating the intelligence of the average BBMP engineer. I really think the junction is going to be a mess, its not been thought out properly, and theyre just going to create confusion. It is going to be really awkward for any bus to take a u-turn like that, and couple that with our bus drivers, and their careless regard for any vehicle on either side of them while they are turning, and it will be a big problem. To see why, lets look at 2 junctions closer to MG Road, on this same route to the airport. The first is just after the planetarium where vehicles coming from Raj Bhavan, take a right to get onto Palace Road (Not sure what the junctions is called - maybe Chalukya junction). Theres 3 lanes of traffic coming from Raj Bhavan, but because the right turn is pretty sharp, and 99% of drivers on the road do not know how to turn without cutting into an adjacent lane, traffic always slows down noticeably at this junction. The second is the next left turn at the High Grounds police station. Vehicles coming up to the junction with Sophia High School and Bangalore Golf Club on their left, inevitably have a problem taking a left - traffic is slowed down a lot since the road is pretty narrow there, and again vehicles turning tend to get into the paths of vehicles in the adjacent lane. Add to this the fact that Sankey Road is at its narrowest at that mouth, just next to the police station the road is barely two lanes. When a bus is turning at either of these junctions, it knocks all other vehicles out of the way and these are pretty much 90-degree turns. Imagine completing a 180-degree turn. Its going to be a nightmare! The obvious and easy solution to this entire rigamarole would have been if they had acquired a bit of land from the Palace Grounds and built a single arm like mentioned above. However the right turn for vehicles coming from Mekhri Circle and trying to get toward Bashyam Circle is also important. Without that right, more vehicles pile up at BDA junction trying to take a u-turn. And since everyone is inconsiderate on the roads, instead of waiting in the right lane for a u-turn, vehicles inevitably end up blocking the middle lane, and restricting traffic moving straight to Windsor Manor, all because they need to take that u-turn. What really gets my goat is the fact that given the size of the Palace Grounds it really wouldnt have driven Wodeyar to bankruptcy and destitution if he had given up some land there. As an erstwhile maharaja he is supposed to care about his people, and that would make the lives of a lot of us easier. Interestingly, hes also planning to sell off chunks of Palace Grounds for thousands of crores (was in Bangalore Mirror recently). If so why couldnt the Palike have just bought a bit of land from him and built atleast the one flyover arm mentioned above. All very irritating. Though of course the Palike may not even have thought to ask Wodeyar for some land to build a flyover - its a wee bit too simple and obvious a solution for our "magic-box" hypnotised authorities.
there is a right turn to
thampan - 28 January, 2008 - 05:06
there is a right turn to sankey road while coming from hebbal. Will that disappear ?
Unfortunately...
idontspam - 28 January, 2008 - 06:40
Though the underpass can hold a single lane comfortably, the notrhbound loop is indeed deeper... more towards the bottom of the picture. Compouning matters is the fact that the authorities have no standard of marking lanes to ensure there are 2 lanes making the U-turn. So expect everybody especially the big buses to cut the corners at the top of the turn and convert it into a chicken neck. This does not take into account the fact that there is no right of way rules that we follow to ensure that the traffic from Bashyam circle merging on to the traffic from Mekhri circle does not obstruct the south bound 2 lane only (still) traffic. Since every body from the north heads all the way past Balabrooie jn. I dont see improvements unless the entire strech is completed and hope for some of the traffic to get off at BDA & Windsor manor. I believe this right turn toward high grounds (lots of interstate buses use it) will also be blocked once the underpass near windsor manor gets built. Which only means traffic from high grounds (not including the ones added from mekhri circle, Cauvery jn, BDA) will get added to sankey road (front of golf course) unregulated without a signal acting as a meter for merge Also, at cauvery jn. even though the south bound traffic is non stop (temporarily no traffic from bashyam circle due to the construction) the traffic is backed up every day all the way to mekhri circle just like it was when the signal existed because of the signal at the BDA junction.
information access.
blrsri - 28 January, 2008 - 08:18
this analysis is truly commendable..considering the lack of information we have about the 'magic' box project! at best I see this as an option for slow uninterrupted traffic flow..but nothing close to what is needed! What about the trailer busses that BMTC has now..it will make other traffic crawl..their tail wags out of control at turns and are bound to hit other vehicles around.. some questions come up here..what is the traffic flow from sankey road towards hebbal, bellary road? From the satellite picture I see one vehicle taking the left turn! Most of the vehicles at the junction are waiting to get into the city.. One solution could be to have bigger underpasses/2 lane each on bellary road itself, which curves a little(10 deg max)..the curve to allow adding of a lane(with fast moving traffic merging on right sign) to traffic moving from sankey road towards windsor manor.. Removing the left from sankey towards mekhri circle(instead that traffic could flow towards windsor manor too and make a U turn around BDA etc).. Can the majic underpasses make U-turns? Btw..deccanherald carried this foto today.. [flickr-photo:id=2225649164,size=m] doesnt it look more like a pedestrian underpass?
Lots more work to be done
idontspam - 29 January, 2008 - 16:44
If my understanding of the windsor manor 'magic' solution is correct. THey are planning to lay an underpass to lead vehicles from high grounds towards raj bhavan on sankey road while the right turn from BDA towards high ground will be banned. This will mean more traffic will get added to the north south sankey road at the windsor manor junction and the substantial traffic that currently turns right will also have to be forced to continue along towards raj bhavan. Today south bound traffic at 7PM was backed up to Le Emridien hotel because BBMP chose to remove the huge tree at the corner near Girias reducing the road to a single lane.
cauvery junction
tsubba - 29 January, 2008 - 03:11
folks thanks for the reply. will get back later.
Cauvery Junction
tsubba - 29 January, 2008 - 16:14
no thampan, i assumed no right turn to simplify. with the right turn there would be an extra phase in the signal. from idontspam's analysis it looks like we will hear a lot about this junction in days to come. you cannot ignore the physics of vehicle movement and hope to get away with it. ids next time around, if you are there can you take a look it and let us know how it has panned out. it ought to be ready by the weekend. i dont think any change in design will happen now. now the only question is, given the underpass, what is a good traffic plan for this junction. they should aim at minimizing the delay for north bound traffic at this junction. that is the most important variable that they need to work on. perhaps some inspired signalling could help. at the very least, S3 can be synchronized with the signal just south of it(BDA junction). (as ids pointed out, despite no cross traffic from sankey road, vehicles are still piling on due to BDA junction.) ids i agree, we need to look at the entire linkage. but i didn't understand this: "Which only means traffic from high grounds (not including the ones added from mekhri circle, Cauvery jn, BDA) will get added to sankey road (front of golf course) unregulated without a signal acting as a meter for merge." i will try and post a reasonable map so that we can discuss in common terms. blrsri, it is not clear if these precast elements are interlocking. there seem to be some sort of holes, but cant make out if it for mating adjacent elements. i am hoping some sort of mating exists other wise earth will start oozing from the gaps between elements. i dont see why magicbox will not be able to turn. need a different type of element, thats all. btw what is the magic of these boxes? how different are these from other pre-cast elements?
info on the 5 underpasses
tsubba - 29 January, 2008 - 18:06
http://bangalore.praja.in/2007/12/17/bial-connectivity-updates Here is the plan for the junctions along the Hebbal Main Road: Windsor Manor Bridge: The BBMP will widen the existing road into a six-lane road with land that has already been taken over from the golf club. Two pre-cast elements will be placed in the middle of the circle to allow vehicles to take a right turn towards Hotel Ashoka, and those coming from Anugraha to come onto to Hebbal Main Road and take a left or right turn. As the lanes will be increased, options to get into Windsor Manor and change lanes to move towards Hebbal or the city are being made. The cost of the project is estimated at Rs 1 crore. It will take seven days to complete it. BDA Junction: Though this is a relatively simpler plan, two long up and down ramps will be made on the Hebbal Main Road. Two box underpasses will allow vehicles to move from Banglore Palace towards Malleswaram, and those coming from Cauvery junction to take a right turn towards Malleshwaram. As the ramps will need embankments, it is estimated that this project will take more time. The cost is estimated at Rs 2.5 crore and will take approximately 45 days to complete. Cauvery Junction: At this junction, vehicles moving towards Hebbal will have to take a left turn towards Bhashyam Circle and then take a 'U' turn after moving 50 meters to join the Hebbal Road. A box will be introduced to take a 'U' turn and another one at the junction, will allow vehicles from Bhashyam Circle to join Hebbal Road and move towards the city. CBI Junction & Sanjaynagar Junction: At both these junctions, underpasses will be erected at the middle of the road below the surface level.
Ok, my bad...
idontspam - 30 January, 2008 - 08:51
Crossing my fingers and hope this works. I will save at least 20 minutes on my commute once the entire stretch is done.
what is the width of the underpass?
thampan - 30 January, 2008 - 11:55
any ideas on 1) what is the width of the underpass 2) what is the turning radius required for a double bodied BMTC bus ? 3) what is the turning radius required for a normal BMTC bus remember the railway overbridge near cantonment station before it was redone. Will this be similar ? ( in terms of turning radius .. etc) I am assuming this will be a single lane traffic from the pictures seen till now.
Underpass model
tsubba - 31 January, 2008 - 12:17
This is the picture of the model of one of the underpasses. DH
labeled this as palace guttahalli. If it is the BDA jn u/p what is that
big cylinder doing in the middle of the road? Though I am happy that
there seem to be slip roads on both sides of the u/p. So how wide is
the main throughfare going to be, 2x2?
ids can you look at the descriptions and see if it all makes sense?
t
have not been able to figure out the widths. am looking for it myself. so what happenned at cant?
BDA junction
idontspam - 31 January, 2008 - 16:23
This is the BDA junction plan. This is how it looks from Palace road (road from mount carmel to sankey road, see palace compound religiously reproduced in the model). North south traffic goes over the underpass. either the model is badly done and not to scale or the real one is going to look this ugly and uncomfortable.
dimensions
tsubba - 5 February, 2008 - 13:42
we have to figure out if x,y and z numbers are sufficient for the whole thing to work. we know underpass is 4.5m wide. we know that there is space for atleast 1 lane(3m) on either side of the underpass. the question is how much space we have after those lanes(x,y) and how long is the underpass(z).
there are prescribed numbers for minimum median width for lane to lane u turns. if we can figure out what that min width of median is, we can see if cauvery junction will work. ofcourse min width means vehicles almost come to stop but are able to turn without going into adjacent lanes. (i am thinking of buses)
guess all this is part of the learning curve. they imposed the extra tight time constraint on themselves. then as sagar pointed out there is geology, then to add to the constraints, metro is supposed to run on this road. lots of constraints. (wonder what happened to the under ground road. )
but more generally, they really have no good options for bellary road. as-it-is it is an important road, now with airport and expected development in the North Bangalore, this road will always be under stress. i think tumkur road, hosur road and bellary road... it goes in that order as far raw numbers are concerned. not a road for piecemeal solutions.
“Slope will be provided at the underpass such that rainwater collects at one point. Grating, a metallic structure, will be placed at the entrance of the underpass to collect rainwater in a chamber, from where the water is made to flow into a nearby storm water drain” It looks like they are now realising the issues with instant underpasses..like water logging..thanks to the ground water logging that happened now. They are now working their brains out to solve issues..however this still leaves a question as to how the contraption will survive this years monsoon! Arent they spending too much money on supporting structures than the actual underpass? Maybe pre-cast flyovers are better though not as fast! http://en.wikipedia.org/wiki/Box_girder_bridge
According to deccan herald,
bcsagar - 4 February, 2008 - 15:54
According to deccan herald, many plans were made & shelved. There is deep hard rock just beneath on Bellary road, so any excavation for underpass had to be done on sankey road part only. But the width of underpass is too narrow (4.5 m). It had to use two adjacent precast tunnel structure. This will be a major bottleneck & whole plan can crash down. The water drainage issue has been solved by connecting to some pit by a chennai co dealig with it. all this is kinda hotch potch job of BBMP.
Also it looks like this pre-cast structure is only going to be good for one lane of traffic. And before this construction started, traffic coming from Bashyam Circle trying to take a right onto Sankey Road toward Windsor Manor could comfortably pile up in 3 lanes at the same junction. If there is only one lane, even if the flow is uninterrupted, I think its going to cause a long queue of cars backlogged towards Bashyam Circle. And god forbid if some idiot breaks down inside the underpass.
underpass pic.
blrsri - 17 February, 2008 - 01:33
[flickr-photo:id=2270387264,size=m] This was there in the deccan yesterday. By the looks of it this can accommodate trailer busses..but sure it would need to slow down quite a bit! This seems ok for normal drivers..but the 'sneak in' category, that bangalore is full of, has the potential to make this a failure! At best these ready made ones are ok for '+'junctions..not for a Y!~ Btw are there any rules for heads of state convoy not to get slowed down at roads, as they can become sitting ducks for any sabotaging?
...they have introduced a new junction just after the cauvery junction further down the road. Probably temporary while the BDA junction work goes on.. I dont know.
Went over the underpass today
idontspam - 20 February, 2008 - 13:01
..and it was exactly like I mentioned. Everybody was piling onto a single lane at the top of the underpass. No lane markings hurriedly done up and out of shape roads.
cauvery junction
tsubba - 20 February, 2008 - 19:27
thanks ids. looking at pics from the past few days it appeared that the pavement was flaky, you just confirmed it. about the piling at the top of the u/p a lot of it is the physics of turning vehicles. you cannot expect people to fight physics just to be in lanes. anyhow, how is the overall experience? is the traffic flowing smoothly? by the time you arrive at CJ from south, apprximately how many columns of traffic are there? i am guessing two bus columns or about 3 car columns. is that right? what happens to all those columns aka 'lanes' when they turn on to sankey road? how are they ensuring that everybody takes a left? do they have a divider or other physical blocks(those clunky metal railing type of things)? and how is the traffic merging back onto bellary road after the turn? have they made any improvements at the turns? some nice and smooth curves like hema malini cheeks or do we have sponge bob type square cuts? keep us updated.
A vague idea that led to ‘magic box’
kbsyed61 - 20 February, 2008 - 22:16
Courtsey: The Hindu Bangalore: The idea of “instant underpass” got life from the memories of Bruhat Bangalore Mahanagara Palike Commissioner S. Subramanya’s visit to the U.K. 14 years ago. It was a team of BBMP engineers and private consultants who gave shape to Commissioner’s “vague” idea and built “magic boxes” to ease traffic problems of the silicon city. Dr. Subramanya said that he was surprised to see an underpass built in three days when he travelled to Sussex in 1994. After he took over as Commissioner, he enquired with his engineers on whether it was possible to build an underpass within a short time. The engineering team – comprising Chief Engineer (Major Roads) K.S. Krishna Reddy, Assistant Executive Engineer Ramakanth Desai, Assistant Engineer K. Chandrashekar — swung into action, consulted a private structural consultant for a solution and succeeded in designing pre-cast elements after analysing city’s road network, particularly the Bellary Road. M.S. Sudarshan, Managing Director, Civil Aid Technoclinic Pvt Ltd, which designed the “magic boxes,” said that it took about 15 to 20 days to design the pre-cast elements after a series of consultation with the BBMP engineers and later it was subjected to field tests. The pre-cast elements had more stability and rigidity compared to conventional beam-method, Mr. Sudarshan said. The width of the pre-cast elements could be extended but it depended on the design of a road where it would be fitted. BBMP used the services of Prof. B.R. Sreenivas Murthy of the civil engineering department of the Indian Institute of Science, pioneer of soil-nailing method, used as alternative for building retaining wall in conventional method. Soil-nailing method saved half the time and cost compared to conventional method, engineering pointed out. The cost of the underpass was about Rs. 1.50 crore despite a delay of 30 days in completing it. Initially, the BBMP proposed to complete it in 72 hours but water leaks and other unexpected problems delayed the completion of work, which was started on January 16. Initially, the cost was estimated at around Rs 1.45 crore. Apart from Rs. 1,5 crore, another Rs. 20 lakh had been spent from the amount earmarked for road, drains and the pavement improvement work for the ward. Lessons Not to commit itself to a short deadline to complete a project is the first lesson that the BBMP learnt when it completed construction of underpass at Cauvery junction on Monday. Commissioner S. Subramanya said that they announced a deadline with good intentions but unexpected problems caused delays. “Still we are happy as we completed the work in a record time of 33 days.” He hoped that the remaining five underpasses would be built by the end of March. The BBMP team learnt many other lessons like draining out water from construction site, executing multiple tasks at a time — without waiting for completion of one work to start the other — earth nailing technology as an alternative to conventional method of constructing retaining wall and so on.
Cauvery Junction Inaugurated
tsubba - 21 February, 2008 - 02:36
(Pic source: ToI)
Design Implications
The design of the underpass reduced the speed of the vehicles to
as
low as 10 kmph (some time dead slow) before taking a U-turn above the
underpass surface. But it has reduced the travelling time by at least
60 per cent between Mehkri Circle and BDA junction. Earlier, vehicle
users were required to wait for nearly 3 to 5 minutes at Cauvery
junction signal. With the construction of the underpass, vehicles will
not stop at the junction although their speed gets reduced. BBMP
Commissioner S. Subramanya said that it would take a week for
people to get used to the U-turn, which was the only possible solution
in shortest time.
Though the underpass has eliminated signal lights at the Cauvery
theatre junction, a fresh manned signal has emerged in the middle of
Cauvery theatre-BDA junction stretch. The manned junction has been
necessitated to facilitate the Vyalikaval-bound vehicles from Mekhri
Circle take a U-turn well before the BDA junction. However, Dr S
Subramanya said the problem would be over once the construction of the
underpass at BDA junction is completed. (DH)
He said: “The outcome of the Cauvery junction underpass will be
evident only after both the BDA circle and Windsor Manor junction
underpasses are ready. “It took 20 minutes on Wednesday to travel from
Mekhri Circle to BDA Circle. Once the works at this junction begins,
commuters will be inconvenienced and further delayed on this stretch.
The impact of all three underpasses can be assessed only after they are
complete,’’ he added. (ToI)
However, absence of pedestrian crossings has become a worrying factor for those who work in the nearby business establishments as they have to risk their life for crossing the roads. He said the BBMP would consider building a skywalk for pedestrians at the junction. The government had plans to start an elevated train service to the airport from the City. “The Palike will go through the alignment prepared for the elevated train and decide where to put the skywalks,” he said. (DH)
Cracks within 72 hours...
(pic source DH)
Roads at the underpass were asphalted only two days before the
inauguration. But they developed cracks within a few minutes after
vehicles started plying. The commissioner said roads developed cracks
at some points where the land was dug to shift utilities. The Palike
has identified such points and repair work will be taken up soon. (DH
Alternative (ToI)
While the debate over the feasibility of the project continues, the
BBMP officials clarified it was a better option than the conventional
underpass, which would have required shifting of utility lines. “BWSSB
authorities demanded Rs 30 crore to shift utilities at three junctions
— Windsor Manor, BDA and Cauvery theatre. The cost of three magic boxes
is Rs 7.5 crore, which is a third of the utility-shifting cost,’’ they
said. The BBMP has vowed to complete the magic boxes from High Grounds
police station to the Hebbal flyover before the first flight takes off
from the new international airport.
Construction of the underpass began on January 15 with the Palike declaring the work would be completed in 72 hours (three days). As a BWSSB water pipeline got ruptured during excavation, the work was delayed forcing the commissioner to seek 10 more days.
The second deadline too was not kept as the seepage of water continued. A horizontal borewell was then sunk through which the seepage water was led into a nearby storm water drain. The work gathered pace once the problem was solved. (DH)
Public Reaction
The new underpass evoked fairly good response among the vehicle
users with a majority of them expressing satisfaction over palike’s
attempt to ease traffic congestion on
Bellary Road.
Although BBMP failed to complete the work in 72-hours as announced
earlier, people said that finishing a project in 35 days, that too with
a low cost of Rs. 1.5 crore, was an achievement by a government agency.
(The Hindu)
“I have been visiting the site for the last 34 days. Often, I felt
there could have a simpler solution. But with time, I began to
appreciate their efforts. The junction is now signal-free. They need to
be careful with their next project as utility lines are all below the
road. Another aspect they need to look into is pedestrian crossings,’’
said 75-year-old K N Visveswariah, retired joint director (agriculture)
and resident of Lower Palace Orchards. (ToI)
Traffic cops hailed the project. But they also rued the lack of
regulation of private vehicles. “Projects like this one provide a
breather to us. But how long will you go on adding infrastructure? We
should freeze the new registrations for some time and encourage public
transport,’’ said a traffic cop on duty. (ToI)
Human Interest
(ToI)
When the magic box underpass at Cauvery junction on T Chowdaiah Road
was thrown open to traffic on Wednesday evening, it created quite a
buzz. Bikers and car drivers could not wait to drive through the ‘box’
to figure out what it was all about.
The BBMP decided on a quiet, informal inauguration, but that could not
prevent a carnival-like atmosphere. While peakhour traffic was caught
unawares, but that did not deter them from waving at the crowds, the
BBMP and police personnel. Pillion riders whistled and clapped as they
drove through the magic box. Motorists were quick to observe the new
signages directed towards Bellary Road and MG Road at the mouth of the
underpass.
Initially billed as a three-day project, it took all of 34 days to be
completed. The eager anticipation of Bangaloreans began to turn into
exasperation. But on Wednesday evening, everyone — curious onlookers,
residents of nearby localities and senior citizens gathered around the
site during the inauguration — agreed it was worth the wait and trouble.
On to BDA Junction
The work on “magic box” underpasses at Windsor Manor and BDA
junction would commence after February 22 depending on the strike by
trucks and other transport vehicles as transporting construction
material had to be ensured before beginning the work, he added.
Deccan Herald
Will it ease traffic or not?, Underpass
is thrown open, finally
The Hindu BBMP
opens its first ‘magic box’
ToI Experience The Magic Feb 21,2008
Cauvery Junction Possible Lane Markings
tsubba - 21 February, 2008 - 03:03
to paraphrase an american nannuDi, if god gave you lemon make lemonade... so herez to the folks at palike trying to make a lemonade off a lemon called as cauvery junction.
here are some ways to make it work ipso facto
#1. get the lane markings right.
(pardon the perspective dissonance, hopefully some newer and nicer images i'll get in days to come to work with. meanwhile solpa adjust maaDi.)
#2. respect the physics of turning vehicles and try to segregate vehicles.
since the top of the underpass is what buses 'naturally' prefer make sure that buses move to the left lane of bellary road so that they are placed to take the top end of the u-turn on the outer lane. cars, bikes & autos can stick to the right lane and take the narrower inner lane to make the u-turn. some nice signages on bellary road 'buses/trucks keep left', 'u-turn ahead' should help.
#3. the yellow hash marks are the ones which will naturally collect dust over the years.
the down ramp and upramp are straight now..instead if there was a curve introduced at the exit of the underpass..I think proabably we would have decreased the U-turn length and curvature which inturn would have resulted in faster travel at the junction! Would like to iterate that these underpasses are better for '+' types of roads not 'Y' jn's!
tried a few things around didn't understand what you meant. can you draw it, take a pic and post/email? rough will do.
like your parent post..
blrsri - 23 February, 2008 - 17:19
[flickr-photo:id=2285610817,size=m]
this could have avoided the u turn and instead made it a wider parabola...
however the ground realities could be all together different..I havent seen the place yet!
photoyogi's pics (http://flickr.com/photos/photoyogi/) low quality drain cover [flickr-photo:id=2285951218,size=m][flickr-photo:id=2285161539,size=m] traffic from bhashyam circle,exit towards cauvery junction [flickr-photo:id=2285950218,size=m][flickr-photo:id=2285950394,size=m] coming back to your point sri, as ids pointed out it is not exactly at the mouth of the junction but deep into the sankey road. i am guessing this so that vehicles from bhasyam circle had a decent ramp. looking at the last picture it appears perhaps they could have tried a box that was not all the way underground. perhaps half underground and half over ground. with ramps to climb over and get down. that would have allowed the underpass to be nearer to the junction.
CJ girder failure
tsubba - 1 March, 2008 - 19:40
A frame of the steel girder on the floor of the Cauvery underpass gave way when a loaded lorry crossed it at about 11 am on Friday. http://deccanherald.com/Content/Mar12008/city2008030154992.asp is this the one shown in yogi's pic?
Finally time to bid Farewell for this Magic
Sanjeev - 31 May, 2016 - 13:00
The city police are all set to close the ‘magic box’ underpass at Cauvery Junction for a few months to felicitate the smooth flow of vehicles heading to Kempegowda International airport (KIA). The magic box will be reopened once the proposed steel flyover from Basaveshwara Circle to Hebbal is commissioned. City Police Commissioner N S Megharik will issue an order regularising the closure once a decision is taken in this regard, said the police.
“The traffic cops wanted to analyse the situation on Monday due to the closure. The police have identified diversions. The closure of the magic box did not cause much inconvenience to the road users from Bhashyam Circle end. The police inspected the situation at the junction in the morning and evening. The situation was more or less normal,” Additional Commissioner of Police (Traffic) R Hithendra told Deccan Herald.
The police said that the magic box was set up in a wrong place which led to blocks and congestions on the stretch between Mekhri Circle and the Windsor Manor bridge. “We will reopen the magic box only after the elevated flyover is thrown open for road users,’’ Hithendra clarified.
http://www.deccanherald.com/content/549641/cauvery-junction-magic-box-closed.html
all magic needs dismantling
srinidhi - 31 May, 2016 - 15:50
I would say all the magic bridges need to be removed on the airport road..
BDA jn/Cauvery/RT ngr/Anand ngr etc..all of them..they are the most unscientific contraptions..
However, this does not mean that a 6 lane steel bridge is the replacement needed..there is a lot of planning needed to manage traffic on this road and engineering is one of the sollution..
For example, the hebbal bridge is only 2 lane wide and how can we expect a 5 lane (3 from bridge + 2 below) merge into this 2 lane?
Way too many questions...and engineering does not have all the answers!
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