New Delhi : Niti Aayog and Indian Railways have come out with a discussion paper for running 150 trains on 100 routes by private operators, envisaging an investment of Rs 22,500 crore.The discussion paper titled 'Private Participation: Passenger Trains' has identified 100 routes, including Mumbai Central-New Delhi, New Delhi- Patna, Allahabad-Pune and Dadar-Vadodara.Other prominent routes include Howrah-Chennai, Howrah Patna, Indore-Okhla, Lucknow-Jammu Tawi, Chennai-Okhla, Anand Vihar-Bhagalpur, Secunderabad-Guwahati and Howrah-Anand Vihar.The paper, prepared for discussions with stakeholders, has split the 100 routes into 10-12 clusters.As per the paper, the private operator will have the right to collect market-linked fares and will be provided flexibility of class composition and halts.The privatisation of train operation, the paper said, will help in introducing modern technology and rolling stocks with reduced maintenance.Besides, it would provide world-class service experience to passengers and also help in reducing the supply demand deficit.The operators could be domestic or international entities, the paper said.Each bidder would eligible for award of maximum three clusters, it added.The Tejas Express on the Lucknow-Delhi route, which was flagged off on October 4, is the railways' first experience of letting a non-railway operator run a train. The Tejas Express is run by railways' subsidiary IRCTC.IRCTC has a slew of benefits worked out for its passengers -- combination meals, free insurance of up to Rs 25 lakh and compensation in case of delays.The Railway Board had in October last year formed an empowered group of secretaries, headed by Niti Aayog CEO Amitabh Kant , to chalk out the modalities of the bidding process and take other decisions to fast-track awarding of bids to private players.