A train every two minutes during rush hours may be a possibility within three years.
Trains on the busiest of the under-construction Metro corridors will be run with increased frequency once they open in 2016. With this, the Delhi Metro will match the peak-hour frequency of the London Underground.
The increased frequency is something the Delhi Metro tried but failed to achieve during the 2010 Commonwealth Games. The failure was attributed to the absence of an advanced signaling system which will be available by 2016.
"We are putting in place a signaling system - a communication based train control (CBTC) system - which can run trains at a frequency of 100 seconds," said an official. The CBTC is a railway signaling system that makes use of the telecommunications between the train and track equipment for traffic management and infrastructure control.
According to Delhi Metro officials, the CBTC system - the latest signaling system - will be placed on Line Seven (Mukundpur-Shiv Vihar) and Line Eight (Janakpuri West-Botanical Garden) - two of the busiest Phase Three lines that together will cater to over four lakh commuters daily.
"The new signaling system will, however, not allow us to increase the length of trains beyond six coaches. We will keep increasing frequency on the two lines as and when there would be a need," said Sharat Sharma, director (operations), Delhi Metro Rail Corporation (DMRC).
The trains on existing busy corridors - Line Two (Gurgaon-Jahangirpuri) and Line Three (Noida-Dwarka) - run at a frequency of nearly two-and-a-half minutes. This frequency - the highest possible in the existing signaling system (automatic train control system) - has failed to cope with the fast-growing commuter rush during peak hours. This prompted the Delhi Metro to start introducing eight-coach trains.