Intelligent traffic signals to ease congestion by 2010

Saturday, February 7, 2009
Source: http://timesofindia.indiatimes.com

These are traffic signals with brains. They take a volume count of the number of vehicles at an intersection and automatically adjust
the available green signal time on the basis of changing traffic demand. And the good news is that Intelligent Traffic Signals (ITS) are going to become a reality in the Capital before the Commonwealth Games.

This is how it works. An area comprised of a group of traffic signals is selected where vehicle detectors are put up on all approach lanes to each intersection. The detectors assess the volume of traffic waiting at an intersection and also the number of vehicles headed towards it from the intersections around. The data is sent to a central server, a master computer, which in turn is connected to the signal controllers or the brains of each of the traffic signals.

The central computer will use electronic signals to instruct the intelligent signal controllers to provide green time to the side with the heaviest stream of traffic, thereby facilitating continuous flow of traffic in that direction. The existing signalling system works on signal cycles, where fixed time frames are pre-set for change of signals irrespective of real-time assessment of traffic.

The system has been designed to optimise utilisation of road space and enable maximum number of vehicles to cross the selected stretch with minimum stoppage at traffic signals. The traffic police feel it is the solution to Delhi's congestion. "Through ITS, it is possible to reduce congestion levels in the selected area. It is being implemented on all routes leading to the Games sites before 2010 and will later be extended to other parts of the city too,'' said S N Shrivastava, joint commissioner of police (traffic).

Experts also feel that it will ease congestion. The systems and algorithms fed into the central computer are aimed at creating an ideal situation where every vehicle entering the road network proceeds without stopping anywhere. But this is not mathematically possible, even in technologically advanced systems. So the busiest corridors are given preference to ease discharge.

To start with, the intelligent signals will be adopted on all roads leading to the Commonwealth Games venues. By 2010, the plan is to have ITS on all 87 corridors spanning across 210 kms which will be used by players and officials. The scheme will cover 302 intersections in all.

In addition to ITS for better traffic management, the selected roads will also be fitted with video cameras to relay real-time images of roads to a centralised control room and give auto alerts in times of jams caused by accidents or vehicular breakdowns. There will also be red light speed cameras and Automatic Number Plate Recognizer (ANPR) cameras which automatically read number plates of vehicles flouting traffic norms and send the data for generation of challan slips and Variable Message Sign (VMS) boards to give road users information about road conditions ahead and prosecution cameras attached to traffic signals.

The traffic police are in the process of finalising the technology which will be used in the Capital. For this, presentations have been scheduled with each of the 21 companies which had participated in a global Expression of Interest (EoI) floated by the traffic police last year. A consultant a JV of RITES and a German firm has been roped in to help in selection of the best available technology
and the bidding process.