Experts believe that the decision to use AC escalated the project cost by 15%, since more digging is required for the rail to work on AC. Despite providing connectivity to Mumbai's airport, passengers on Metro 3 will not be permitted to carry their check-in luggage onboard trains. Only hand/cabin baggage will be allowed. MMRC officials stated that Metro 3 was not an "Airport Express line", but a regular city metro corridor. Officials explained that providing luggage check-in would require additional dwell time at the Airport metro station, which would increase the overall headway of the line, and disrupt services for other passengers. Metro 3 will utilize an open loop automated fare collection system. Passengers will be able to pay for travel using contactless pre-paid and post-paid smart cards issued by partnering banks. Only RuPay debit and credit cards will be accepted on Metro 3. In March 2017, the MMRC held a pre-bid meeting with all pre-qualified bidders for the "Design, Manufacture, Supply, Installation, Testing and Commissioning of Tunnel Ventilation & Environmental Control System." In the same month, the agency received 12 bids from consortia to set up an automatic fare collection system. In March 2020, MMRC expressed its displeasure over Tata Power's revised electricity tariffs and announced it could result in higher fares for passengers when the line opens.