When the West Bengal government decided to drastically scale back Kolkata’s 150-year-old tram service, leaving just a short heritage stretch from Maidan to Esplanade, it ignited a wave of protests from environmentalists and tram enthusiasts alike. The official reasoning – low speed and road congestion – fails to hold up under academic scrutiny.

Trams, with their speed averaging 20 to 30 kilometers per hour, match the pace of most public transport in the city, including buses. On busy roads, where traffic flow is already slow, why single out trams as the root cause for congestion? A closer look reveals that the real bottlenecks are caused by smaller vehicles such as auto-rickshaws and private cars, which clog lanes designated for trams, slowing their operations.

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About autos, the less said the better. They are a law unto themselves, following minimal traffic rules and the traffic police has little power to discipline them. No doubt, theautos, charging higher fares for shorter distances and accommodating only three to five passengers at a time, are less efficient and more expensive than trams, which can carry 200-300 passengers per trip at far lower costs. Rational commuters, if given a choice, would likely opt for trams more spacious, economical, and practical for urban mobility. Worldwide, tramsare witnessing a big comeback given the multiple advantages of the same vis-à-vis other modes of public transport. Beyond addressing these misconceptions, the debate over trams opens a broader conversation about sustainability in urban transportation.

Trams, with an impressive lifespan of up to 80 years, consume less energy (0.017 kWh per place kilometer.) compared with traditional diesel and natural gas buses (about 0.080 kWh per place kilometer). Incidentally, battery-operated buses (BEBs) consume energy to the tune of 0.67 kWh/km, about 40 times more than a tram. Thinking of the net-zero carbon emission target,BEBs have been adopted in many states of India and in Kolkata as well, requiring frequent and costly battery replacements, where trams offer unmatched durability, are equally environment friendly and have lower lifecycle costs.

With transportation contributing significantly to urban air pollution and greenhouse gas emissions, reviving and expanding the tram network could be a game-changer for Kolkata. Yet, instead of harnessing their potential, the city’s transport policy appears to prioritize costlier and less efficient alternatives, raising a critical question: are we making short-term tradeoffs at the expense of long-term sustainability? Typically, a tram or bus unit runs approximately 1,500 kilometers in a month.

Let us assume that Single Carriage Trams operate with average passenger occupancy of 100 per trip, considering that in a day the number of passengers will vary, and 20 trams run daily across the city. Each tram and busoperates from 6 AM to 10 PM, totaling 16 operational hours or 960 minutes. By contrast, BEBs require charge on-route with 6–8 minutes of charging at 450 kW for every hour of operation. So, on an approximate basis,let’s consider 800 operational minutes (approximately 12-13 hours). On average, each vehicle completes three round trips daily between points A and B, requiring two hours per round trip, resulting in six single trips per unit.

To maintain service intervals of every 15 minutes in zones like north Kolkata, where four trams operate per hour, buses (BEBs) would need to almost double the number of vehicles to match tram capacity, along with additional fleet to cope up with the battery charging time and given their smaller passenger capacity of 40-50. Thus, if 20 trams are operational, 40 buseswith 10 more buses would be required considering the charging time. Both trams and BEBs charge fares between Rs10 and Rs20, so we are assuming Rs20 for both making ticket revenue comparable. In terms of lifespan, a tram lasts eight times more than BEBs. On the other hand, BEBs incur battery replacement costs of Rs2.5 lakh every five years.

Leaving aside the inflation part which will be applicable for both trams and BEBs, let us examine the hard facts from life cycle analysis of trams/BEBs. In the analysis, we have considered both the fixed cost and operating cost of carrying the same level of passengers in either modesto understand the long-run implication and also sustainability keeping environment as top priority. Now, imagine this: over 80 years, trams operate seamlessly with costs that are around 70 per cent lower than BEBs.

Why? Trams are built to last, with minimal maintenance and no need for any major replacements during their lifespan. In contrast, BEBs require sixteen replacements of batteries over the same period. Doesn’t that sound like a significant financial burden? Now, think about revenue. At aRs20 fare, BEBs generate nearly a loss of 214.11 per cent which is almost double the percentage relative to the tram’s profit margin over 80 years.Also, no matter over 80 years, even in its single life span it runs at a loss of Rs. 51crore, which is a reason to rethink our decisions.

More surprisingly when there is a need for an additional fleetto fill the time for charging, it will be running in huge loss. Tramsoutperform BEBs more efficiently, proving their efficiency in lower-revenue scenarios. In addition to these, the total cost which includes the fixed and operating costs is almost 3.2 times lower for trams than BEBs accounting for 70 per cent savings if we invest in trams over BEBs.

So, what’s the best way forward for Kolkata? Modernizing the city’s historic tram network could be the game changer. Trams are not only cost-efficient but also environmentally friendly, offering a sustainable solution for high-density zones. So, it’s time to rethink what to adopt now, because that will decide whether a metro like Kolkata will have an affordable, efficient urban transport system orKolkatanswill be at the mercy of autos.

(The writers are, respectively, a Research Associate and Professor at National Council of Applied Economic Research (NCAER), New Delhi. Views are personal.)