Effect of Road Traffic on Air Pollution. Experimental Evidence from COVID-19 Lockdown

Abstract

The increasing concentration of human activities in cities has been leading to a worsening in air quality, thus negatively affecting the lives and health of humans living in urban contexts. Transport is one of the main sources of pollution in such environments. Several local authorities have therefore implemented strict traffic-restriction measures. The aim of this paper is to evaluate the effectiveness and limitations of these interventions, by analyzing the relationship between traffic flows and air quality. The used dataset contains concentrations of NO, NO2, NOx and PM10, vehicle counts and meteorology, all collected during the COVID-19 lockdown in the city of Padova (Italy), in which severe limitations to contain the spread of the virus simulated long and large-scale traffic restrictions in normal conditions. In particular, statistical tests, correlation analyses and multivariate linear regression models were applied to non-rainy days in 2020, 2018 and 2017, in order to isolate the effect of traffic. Analysis indicated that vehicle flows significantly affect NO, NO2, and NOx concentrations, although no evidence of a relationship between traffic and PM10 was highlighted. According to this perspective, measures to limit traffic flows seem to be effective in improving air quality only in terms of reducing nitrogen oxide.

Social-distancing Fatigue: Evidence from Real-time Crowd-sourced Traffic Data

“…19 The study in Padova found a decrease in traffic flow (vehicle counts per unit time) in 2020 of approximately 70%, compared to 2018-2017. 18 Similarly, the study in Auckland found a 60-80% decrease in traffic flow following travel restrictions implemented in response to the pandemic. 19 Another analysis of traffic changes in the NYC metro area found reductions of 66% in passenger vehicle traffic the week of March 28-April 3.…”

“…Dramatic decreases in traffic have been noted in NYC 17 and many other places 18–21 in response to the pandemic, including Padova, Italy 18 and Auckland, New Zealand. 19 The study in Padova found a decrease in traffic flow (vehicle counts per unit time) in 2020 of approximately 70%, compared to 2018-2017.…”

“…However, studies in other cities also find dramatic decreases in traffic, on a similar scale as that reported here. 18,19,21 Second, our data source does not allow for disaggregation of passenger vehicles and trucks, which were likely differentially impacted by responses to the pandemic (as trucking operations may be considered essential businesses). Studies in NYC 27 and Somerville MA 20 have found decreases in both vehicles and trucks, though the decrease was substantially less for trucks.…”

Feature Engineering Algorithms for Traffic Dataset

“…Researchers are looking for creative solutions like smart cities and GIS systems to avoid traffic congestion and volume [2,3]. A study conducted reveals that traffic volume has a significant impact on P M 10 , N O x , N O, and N O 2 concentrations [4]. [5]'s study shows that the increase of the vehicle increases the concentrations of air pollution during peak hours in the morning and evening.…”

Source Apportionment of Ambient Black Carbon during the COVID-19 Lockdown

“…Besides its devastating global effects on public health, economy, daily habits, and social life, people around the world have witnessed remarkable improvements and recoveries in almost all compartments of the environment in virtue of imposed lockdown measures to stop the spread of the COVID-19 pandemic [54][55][56][57]. One of the most significant benefits of COVID-19 lockdowns was probably on the public's enhanced quality-adjusted life years in parallel with the increased air quality reported for many regions of the world [58][59][60][61][62][63][64][65]. A few studies have been conducted to reveal the impacts of COVID-19 lockdown measures on ambient BC concentrations.…”