India, May 22 -- Some may call it a success story. But for frequent users of Metro 1, their patience is wearing thin. Long wait times on narrow, overcrowded platforms and a shoulder-to-shoulder commute during peak hours in closed air-conditioned coaches is not what the city promised when it flagged off Mumbai's first metro rail corridor a decade ago.

Over the last couple of days, frustration has been spilling over on this Versova-Andheri-Ghatkopar metro corridor. The stations at Ghatkopar, Andheri and Marol are particularly congested. An average 114,500 commuters use Ghatkopar station daily, 83,000 Andheri, and Marol Naka and Saki Naka more than 40,000 a day.

During the week, at least twice, passengers complained about stubborn queues n...