Bengaluru: The Railway Board has accorded in-principle approval for the CBTC signalling and train control system for BMRCL's Pink Line as well as the entire Blue Line-phase 2A and 2B extending up to Kempegowda International Airport, metro officials said on Saturday.The Communications-Based Train Control (CBTC) system approval is an important milestone towards commissioning the Pink Line between Kalena Agrahara and Tavarekere, they said.BMRCL has been intensely following up with the Railway Board and RDSO (Research Designs and Standards Organisation) during the last one month to facilitate completion of the approval process, officials said.Significantly, the same approval also covers the Blue Line from Central Silk Board to Kempegowda International Airport, they said.Read More: Railways imposes Rs 5.13 cr fine, terminates 6 contracts and debars defaulting licensees for food quality violations in last 3 yearsIn a statement, the Bangalore Metro Rail Corporation Limited said that while the signalling clearance was a pending milestone for the Pink Line, for the Blue Line it has been secured well in advance of its proposed commissioning, facilitating timely testing and safety certification."For the Pink Line, BMRCL will now proceed with the remaining steps towards commencement of passenger services: interim speed certification from RDSO, statutory inspection of the rolling stock by CCRS, trial runs, and thereafter the final statutory inspection and clearance for opening the line for public use," it said.BMRCL added that it will continue to closely coordinate with all concerned agencies to complete these remaining processes at the earliest.