Constituting 88% of total trips, public transport in Kolkata, Mumbai has led to lower vehicular pollution: Study

Counterview Desk
A new study of urban vehicular  pollution has said that Kolkata and Mumbai “emit least among six megacities due to high usage of public transport and walking”. According to the study “Kolkata ranks sixth among all the 14 cities, but it wins among the six megacities”, and does better than Pune and Ahmedabad, because “the average distance travelled by different modes in Kolkata is lowest among all megacities.”
Carried out by Anumita Roychowdhury and Gaurav Dubey of the Centre for Science and Environment (CSE), New Delhi, and supported by the MacArthur Foundation of Chicago, the study says, “Kolkata also has the lowest vehicle stock among the megacities and second highest share of public transport”, adding, “About 60% of all its travel trips are within 3–4 km. This is exactly the model that Japanese cities and Hong Kong have followed.”
Titled “The Urban Commute: And how it contributes to pollution and energy consumption”, the study says, “ Kolkata has the most diverse public transport system for urban commuting – buses (now upgrading to electric buses), metro, trams, suburban rail, para-transit and waterways. If the share of public transport and para-transit are combined, they constitute 88% of the total trips in the city.”
“This shows that only high population, high travel volume and economic growth need not necessarily lead to higher automobile dependency”, comment authors, adding, “Early investment in diverse and connected public transport, and physical restraints can help. Kolkata’s public transport culture, compact city design, high street density, short travel distances and restricted availability of land for roads and parking are among the good practices. It helps reduce overall emissions and guzzling.”
Mumbai, ranking next to Kolkata among megacities, also wins, says the study, “as a result of its public transport spine – primarily its suburban rail system. Public transport and para-transit add up to 89% of all motorized trips in Mumbai.”

“Interestingly”, the study says, “Mumbai has one of the highest trip length for personal vehicles and yet its overall guzzling and emissions are comparatively lower as its suburban rail, which has zero local emissions, meets 52% of the travel demand in the city. Thus, despite having highest trip generation and volume of travel Mumbai could reduce negative impacts by adopting an intelligent public transport strategy.”
Comment the authors, “Mumbai has also proved that economic growth need not necessarily translate into high personal vehicle dependence. Even with highest per capita GDP among the six megacities and highest volume of trip generation, use of personal modes is lowest in Mumbai. This has helped Mumbai to have lower emissions and guzzling compared to most other megacities.”
Pointing towards why Delhi ranks worse of not just six metropolitan cities but also all the 14 cities studied, the study says, this could be because of megaciy's “current abysmal level of walking and public transport”, resulting in “a massive scale of overall emissions, pollution and energy guzzling.” Added to this is “sheer effect of population, volume of travel and highest vehicle stock”, all of which “eclipses the benefits of having CNG and better travel parameters than other cities.”
Thus, Delhi emits 5 times more particulate matter (PM) emission load from urban commuting than Kolkata, and 3 times more than Mumbai, 13 times more than Bhopal, 9 times more than Chandigarh and 8 times more than Vijayawada. And as for CO2, Delhi emits 4 times higher than Kolkata, 2.3 times higher than Mumbai, 1.7 times higher than Hyderabad.
As for other cities, the study warns, “Ahmedabad, Lucknow, Vijayawada, Pune and Jaipur are at an inflection point. Their per trip emissions are in the middle of the spectrum, and depending on what direction their mobility policies take over the next years and decades, their pollution levels may increase or decrease accordingly. They need to take corrective measures now and avoid the fate of the megacities.”
An assessment of 14 cities, based on emissions of heat-trapping carbon dioxide and toxic pollutants of particulate matter and nitrogen oxides, as well as energy guzzling from urban commuting, the ranking, says the study, is based on aggregated overall emissions and energy use from the urban commute by combining the overall quantum of aggregated toxic emissions of PM and nitrogen oxides (NOx), heat-trapping carbon dioxide (CO2 ) and energy consumption from urban commuting practices.