Delhi: Cars vs pollution 2023
Why this study?
A CNG bus can replace 40 petrol cars. That is equivalent to 4 times less NOx emissions. Commuters do not realise the importance of their mobility choices, and the impact it can have on the environment.
This analysis of air quality monitoring stations around the selected routes for travel speed analysis highlights the significant environmental implications of congestion, emphasizing the need for effective traffic and pollution management strategies, and for promoting sustainable mobility strategies…
Choked roads, choked throats..
Delhi faces deadly pollution levels during winter, specifically around November, when the number of farm fires in Punjab and Haryana increase substantially after farmers are done cultivating rice in late October, and they need to prepare fields for the winter wheat crop in a short window. During this period, AQI reaches ‘Severe’ and ‘Severe+’ levels according to Central Pollution Control Board’s scale. And cars make it worse for us..
Vehicular emissions account for 38% of Delhi’s pollution…
Vehicles contribute largely to nitrogen oxides (NOx) emissions, which contributes to smog, and can cause respiratory infections, and worsen lung diseases. Presence of NOx in the air also leads to production of Ozone (O3), through chemical reactions in the atmosphere. O3 is also a major factor for smog in the city. Carbon monoxide (CO), and sulphur dioxide (SO2) are the other two pollutants released from tailpipes. Vehicles do emit particulate matter (PM) emissions, mostly PM 2.5, especially in diesel engines, however the share is lower than NOx and CO.
Congestion links to higher emission levels, impacting the micro-environment.
The data reveals a distinct direct correlation between emissions and congestion levels. This relationship is particularly evident when observing how the dips in travel speed (valleys) align with spikes in NO2 concentration at corresponding times. The provided graphs offer a more detailed perspective, illustrating the variation in NO2 and O3 concentrations across different routes. These fluctuations are notably distinct between peak traffic hours and off-peak periods, underscoring the impact of vehicular flow on air quality.
In 2023, AQI breached the ‘Severe’ limit in Delhi in the first week of November. Since then, the AQI has hovered over the 400 mark for over a week, until untimely rains on November 10th brought the AQI down to 150-200. However, right after Diwali, 13th November onwards, the AQI average bounced back between 300-350 until November 20th.
During all this, GRAP measures were applied in the entire city, banning BS III cars, and BS IV diesel cars to ply on the roads. The government was also anticipating the ‘odd-even rule’ which is Delhi government classic band-aid solution to limit cars on the roads by allowing even registration plates to only run on even days, and vice versa. It was later discarded after the rain. Ironically, Delhi was also planning to induce artificial rains in the capital.