[vharihar]

I have seen sensor-based traffic signals very commonly used in the USA. I first saw them in the US in 1993. It likely was already prevalent many years prior to 1993. Nowadays, it is ubiquitous, present in about 90% of all traffic signals in the US, not just in big cities but even in small towns. Not just traffic signals, they are also present on freeways (ie. highways) to sense flow/stoppage of traffic, and I have also seen them in between 2 traffic lights on surface streets (ie. non-freeways).

Most of these sensors are based on an induction loop embedded just below the road surface under every lane at a junction. See an image at http://en.wikipedia.org/wiki/File:In..._detectors.jpg . You can see the circular (about 2 meters diameter) or octagonal grooves covered up with tar linings. Thats where the sensors are embedded sub-surface.

These sensors are connected to a Micro-Controller based System (MCS) that acts on the sensor being activated. These MCS's can have one of various kinds of algorithms, that, besides the sensor activation inputs, take into consideration things priority of carriageways, rush hour direction at that time of day, synchronized to a neighboring signal in both perpendicular directions, etc. The technology and its effectiveness (that I have witnessed for 20 years in the US) amazes me. So much so that recently I suggested my child to do a project on it.

Using this technology needs strict adherence to road construction standards Eg. when repaving a road, use a milling machine to dig out the old layer, carefully take out and preserve the induction loops, and reinstall them using a groove cutter after repaving (see http://www.lochwynd.com/cutting3.jpg for a picture), etc.

Question:
I recently came across a March 2008 article saying Ahmedabad is introducing this technology. See http://www.expressindia.com/latest-n...-roads/279227/. Has this been implemented in Ahmedabad? Any other Indian cities too? How is it working out?

[Wind]

I had occasionally read abound sensor based signals being implemented in Bangalore but do not know whether any of the systems has seen the light of the day . Here is one such report that came in 2007

The Hindu : Karnataka / Bangalore News : Bangalore to have new traffic control system

-- Wind

[shivmarwaha]

Delhi has been using these for more than a decade. The first system that was implemented in delhi was in the new delhi area caked as the ATS. Now this is being implemented in the other areas also. I know of this system because we helped delhi police conduct traffic studies. The first highway traffic management system executed by Siemens for NHAI on NH8 also use this system. We have implemented induction loop counters for vehicle count and vehicle classification at the many toll plazas designed by us.

[vinair]

These were installed at the BEL circle and Hebbala circle in Bangalore few years ago, these were manufactured by BEL and were quite effective.

[Warwithwheels]

Originally Posted by vharihar

............Question:
I recently came across a March 2008 article saying Ahmedabad is introducing this technology. See http://www.expressindia.com/latest-n...-roads/279227/. Has this been implemented in Ahmedabad? Any other Indian cities too? How is it working out?

The whole concept sounds interesting. But the links you posted appear to be broken except the 2nd one. Can you please repost them?

[aroop]

Kolkata has these, as per a recent report of malfunction of these (thanks to pwd digging the wires with elan).

These are manufactured by Keltron

m.timesofindia.com/city/kolkata/Wrong-signals-for-city-traffic/articleshow/14379135.cms

[Neilguy]

Originally Posted by Warwithwheels

The whole concept sounds interesting. But the links you posted appear to be broken except the 2nd one. Can you please repost them?

I believe these were the missing links the thread starter was trying to link:

Inductance Detectors

Sensor-based traffic signals to ease congestion on Ahmedabad roads - Express India

[shashi63]

Hello,

I guess that the reply to this is pretty old.. but since i do have some knowledge on this I would ask you to check with CDAC Trivandrum on recent developments. CDAC has for teh first time introduced and successfully implemented Area Traffic Control systems based on Indian Traffic Conditions and yes they use detector loops at junctions.

Regards
Shashi

[shashi63]

Correct!

Keltron has a technology tie-up witH CDAC to Manufacture Area Traffic Control Systems.. Most ATCS of foreign origin do not work properly in India due to our traffic and road conditions. The one developed by CDAC is something we Indian's should be proud of and works on a technology which has been proven in India.. the first pilot was done in Jaipur which then got implemented in a big way at Pune.. then Jaipur got expanded and then Kolkata..

If anyone needs any information on this is welcome to contact me

Cheers!

Shashi

Originally Posted by aroop

Kolkata has these, as per a recent report of malfunction of these (thanks to pwd digging the wires with elan).

These are manufactured by Keltron

m.timesofindia.com/city/kolkata/Wrong-signals-for-city-traffic/articleshow/14379135.cms