Officials add that increasing the frequency of AC services is another step towards easing congestion.In the wake of Central Railway (CR) and Western Railway (WR) expanding their network of AC local trains, commuters complain that persistent delays and unreliable service substitutions continue to plague Mumbai’s suburban rail system. From May 1, CR converted 14 non-AC suburban services to AC, while WR transformed 12 non-AC locals, taking their total AC services to 108 and 145, respectively.Despite the expansion, AC services are running into chronic delays, often inconveniencing passengers. “I usually take the evening fast AC local train to Kalyan, and almost inevitably it is held back by a minimum of 10 to 15 minutes,” said Varsha Dasani, a 38-year-old commuter who travels daily from Chhatrapati Shivaji Maharaj Terminus (CSMT). With few viable alternatives amid Mumbai’s stifling heat, she says she has come to accept the delay as part of her routine.Such disruptions have a cascading effect across the network. Even a brief delay in the departure of an AC local can push back subsequent non-AC services, increasing wait times for general passengers. “My non-AC local was delayed by 20 minutes because an AC train from Virar arrived late,” said a 51-year-old passenger travelling from Churchgate railway station one afternoon.While similar complaints have emerged from non-AC commuters, railway officials maintain that delays are systemic rather than limited to a particular service type. “If any part of the system gets delayed, it affects the trailing services as well,” said a senior railway executive. The issue is compounded by what officials describe as over-utilisation of track capacity, with Mumbai’s suburban network currently operating at 120% to 130% capacity, leaving minimal buffer between train movements and affecting punctuality.Apart from scheduling constraints, AC suburban services are also grappling with overcrowding. During peak hours, large crowds attempting to board AC trains often block the sensor-controlled automatic doors, delaying departures until they can fully close. In one instance earlier this year, an AC service between Thane and Kalyan reportedly ran with its doors open after commuters crowded near the entryways, highlighting the strain on these services.In response, authorities say they have initiated remedial measures, including deploying personnel from the Railway Protection Force (RPF) and the Government Railway Police (GRP) along with ticketing staff to manage crowds. Queueing protocols have also been introduced at busy stations to streamline boarding. In February, WR implemented a colour-coded queueing system at Nalasopara railway station, prioritising alighting passengers before allowing others to board.Officials add that increasing the frequency of AC services is another step towards easing congestion. “We have doubled the number of AC locals on the Harbour line from 14 to 28, considering rising passenger demand. CR has also added an AC service during the morning peak and a corresponding one in the evening,” said Swapnil Nila, Chief Public Relations Officer of Central Railway. With more AC rakes expected to be inducted, officials say any crowding pressures will gradually ease.Story continues below this adHowever, commuters argue that these measures do not address unreliable substitutions and poor communication. Sudden switches between AC and non-AC services without timely updates often leave passengers stranded. Ruth Vaity, a 23-year-old student commuting from Dahisar to Churchgate, said she frequently learns of such changes only on reaching the platform. “I end up skipping my train when it is converted into an AC service and wait for the next non-AC local,” she said. The issue is particularly acute at smaller stations, where display boards often fail to reflect real-time changes, forcing commuters to rely on apps like M-indicator.Passengers also point to the price disparity between AC and non-AC services. “A commuter holding a Rs 105 AC ticket feels deceived when the service is replaced by a non-AC train, forcing a choice between travelling in a non-AC train or waiting significantly longer for another AC train,” said Lata Argade, president of the Suburban Railway Passengers’ Federation. Argade also argues that passengers are rarely compensated for the fare difference in such instances.AC suburban services in Mumbai have expanded steadily over the years. WR introduced its first AC local in 2017 on the Borivali–Churchgate route, while CR launched AC services on the Main line in 2020 between CSMT and Kalyan. However, AC services on the Harbour line were introduced much later, in January 2026. Currently, the Main line runs 80 AC services, while the Harbour line operates 28.AC services form 5.9% of the total 1820 daily suburban services run by the CR. Meanwhile, 10.3% of WR’s 1414 daily suburban services operate as AC trains.