Of these, three including the prototype being tested, have already arrived at Mundka depot,' Dayal said.

The spokesperson said after obtaining necessary clearances from Lucknow-based Research Designs and Standards Organisation (RDSO) by the first week of August, more trial runs would be conducted.

The trains are equipped with Closed Circuit Television (CCTV) cameras inside and outside the coaches, power supply connections to charge mobiles and laptops, better humidity control, microprocessor controlled disc brakes, and external display boards on side windows of each coach.

The Inderlok-Mundka line is slated for completion by March 2010. However, DMRC officials claim that it will be opened to public by the end of this year.

Cities like Cairo, Madrid, Bangkok, Manila and Beijing operate on standard gauge keeping in mind Metro alignments have to pass through heavily congested areas and standard gauge permits sharper curves.

'Constant upgradation of technology for standard gauge coaches take place worldwide,' Dayal added.