Bengaluru gets a lesson in designing interoperability

Starting June 2026, BMTC buses begin accepting the National Common Mobility Card under India’s One Nation One Card framework, which also works on Namma Metro. One card, multiple modes — and, eventually, multiple cities. Bengaluru loses an estimated 700,000 productive hours each year to traffic; the city’s metro is expanding to cover 175 km this year. The card existed for three years before it worked across modes — because BMTC’s News Source: ANI machines couldn’t read it. That delay is the design lesson in interoperability. Cards don’t solve congestion. But they remove friction at the seams between modes — which is where most public transport users actually drop out. The deeper signal: India is learning (the hard way) to design systems before it finishes building transit options. Interoperability is the cheaper when systems are being designed than upgrading later.

Interoperability is the cheaper when systems are being designed than upgrading later.