Thread by @manasipkumar

The tragic death of a 22yo in Bangalore as her car submerged in the rains at KR circle brings us back to the labyrinth that is #bangaloretraffic. Clearly we have it terribly wrong. But where did it start? Why do our underpasses flood? Somebody should ask him - Dr S Subramya

#Subramanya became the BBMP commissioner in 2007, handpicked by #hdkumaraswamy. Bangalore was growing exponentially. We had shut down HAL and the swanky new Bangalore airport had come up (close to Goa). The Cauvery Junction was pivotal to the smooth flowing traffic to the airport

#subramanya came up with the idea of an underpass which was (rechristened as magic box) at the junction. This was the first of its kind infrastructure experiment in the country. The idea was to make Mekhri Circle a signal free corridor and year was 2008. This was his brainchild.

It was called a magic box because on could easily set it up in less than a month. Given the time taken to complete infrastructure projects, this was magic, I suppose. The original placing of the box had to be changed because the BBMP had not considered the water lines under it.

So they had rework the design and the current placement was built in 35 days! What it did was add chaos to the confusion . But magic boxes became the buzzword for building underpasses in Bangalore. We have about 29 underpasses in the city. @srinualavilli can you confirm?

The advantage of these magic boxes as opposed to traditional underpasses was that they cost a fraction of the latter and could be built in less than two months! The #bbmp had hit a jackpot.Or do they thought. They even appointed a patent attorney to claim copyright for the design

These magic boxes were were seven and half meter wide, made of precast material for double lane underpasses. The Cauvery junction which was a single lane box was about 4.5 meter wide. But let’s go back a bit and understand why and where do we need underpasses and what they are.

Underpasses are grade separators like flyovers which are put in place after PCU or per car unit surpasses the stipulated numbers. They are the last resort. Here is how traffic infrastructure measures are decided.

Cauvery Junction, Tagore Circle & the now infamous KR Circle underpass were among these magicbox fixes. They regularly flood everytime the skies open up. When the design first came up, the experts were divided about it. MN Sreehari,member of the Traffic Advisory Committee said..

“the problem is that once the box is placed, there is usually a slope on either edge of the magic box, which must be filled with sand and pieces of stone. It is next to impossible to do this with precision, manually....

...This causes the boxes to be weak — when it rains, water gets collected at the two ends of the magic boxes, and we have swimming pools on the edges. The whole road is exposed to risk. You only have to look at the magic box on Bellary Road to see what I mean”

The design soundness of magic boxes was already being called out by in-house experts but the BBMP ploughed on with it. It was meant to be Subramanya’s legacy as the commissioner. However TGS George has famously called magic boxes as ‘Subramanya’s revenge’ on Bangaloreans.

And the former commissioner was not without his share of controversies. In 2009, 6 yo Abhishek fell into a storm water drain and his body was never recovered which created an embarrassment to the govt after Lokayukta Justice Santosh Hedge chided the BBMP over its incompetence.

subramanya had filed a defamation suit against Justice Hegde which he withdrew only after #BSY intervened. He also approved the #GKVK road project where more than 900 trees were cut. The BBMP decided to serve him a show cause notice to him for the same. He had retired by then.

@leofsaldanha can you give more details on that project of #GKVK? Having said that, does anyone know where this guy is? Can someone interview him about the logic behind these designs that have now killed a young girl? Accountability needs to start somewhere.

Less 3000 PCU (per hour)- no intervention needed. Over 3000 - a rotary or circle is needed. Over 5000 PCU - a signal is needed. Over 10000 PCU - a grade separator is planned.