NEW DELHI — Stringent policies to restrict vehicular pollution are imperative to tackle the problems of increasing urban air pollution — a major health concern — in the country, said Indian Institute of Technology (IIT) Bombay researchers in a study on Wednesday. Emissions from motor vehicles are major contributors to urban air pollution in India. The longer time vehicles spend on the roads leads to a large amount of fuel being burned, thus resulting in more pollution. However, the polluting characteristics of all vehicles are not the same as some vehicles release disproportionately higher amounts of pollutants. The study investigated factors determining the characteristics of high-emitting vehicles, also known as super-emitters. “Until now, there has been no study in India that has examined the share of super-emitters in real-world vehicular fleets. The previous studies assumed their share based on literature from other countries or secondary data. The motivation was to reduce uncertainty in the emission estimation from real-world vehicular fleets,” said Sohana Debbarma, a researcher who conducted the study. The researchers explained that super-emitters were vehicles that were either old, poorly maintained, over-loaded heavy-duty vehicles or all of them. They release significantly higher amounts of pollutants compared to other vehicles...