Study shows how mobility policies can contribute to improving air quality

Developed by researchers from the Center for Innovation in Public Policies (FGV Cidades) of the São Paulo School of Business Administration (FGV EAESP), the "Shared Streets" project provides evidence of how urban public policies are central to reducing air pollution. The problem was the reason for an alert released last week by the Environmental Agency of the Government of São Paulo (Cetesb), which identified a drop in air quality in February 2024.

According to the Cetesb report, the air was classified as bad in seven of the fifteen stations installed in different neighborhoods of the city. In eleven other neighborhoods, pollution was considered moderate. And in one of them, Pinheiros, the air was pointed out as very bad. The main reason for this drop in air quality is the concentration of pollutants formed by the burning of fuels.

The very distribution of space allocated to each mode of transport illustrates the origin of the problem of high levels of pollutant emissions in the municipality, which lies in the prioritization of individual motorized transport.

According to the FGV Cidades survey, 60.8% of the street area in São Paulo is dedicated to automobiles, which is equivalent to more than 9 times that explored by motorized public transport (6.5%), 20 times the space dedicated exclusively to buses (2.9%) and three times the area dedicated to sidewalks with adequate width for pedestrian circulation (17.1%).

When analyzing the environmental impacts of this prioritization, it was found that automobiles and motorcycles together are responsible for 75.4% of emissions, practically triple the daily emissions of 24.6% of buses (municipal and highway combined).

"We know that individual trips account for 30% of total trips, but they contribute more than 75% of greenhouse gas emissions. That in itself is a major distortion of the negative externality cost of each of these modes. So, I think this demonstrates a little and could guide very pertinent discussions such as the collection of urban tolls for automobiles," said FGV Cidades researcher Frederico Roman Ramos, who was part of the project team.

The social impacts of prioritizing individual motorized transport were measured, analyzing aspects such as air pollution, congestion time, traffic accidents, and health impacts resulting from the excess emission of fine particulate matter.

"Moving 1% of passengers from individual transport to buses would generate a net reduction of 1.38% in emissions. With the current price of the carbon credit (75 euros) and the total volume of daily emissions in the municipality of São Paulo (10 thousand tons of CO2e), the change of 1% of TPI users to the bus would generate savings of approximately 10.3 thousand euros per day", said Frederico.

The project compared the negative externalities generated by the different modes of transport. Based on data from the São Paulo Atmospheric Emissions Inventory, produced by the Institute of Energy and Environment in 2017, greenhouse gas (GHG) emissions and contaminants were estimated.

In addition to assessing the economic and social costs of externalities, a case study was carried out in the East Zone region of São Paulo, to assess the potential demand and the impacts of investment in non-motorized transport.

Health and Costs of Poor Air Quality

Data from the World Air Quality Report 2023 show that only seven of the 134 countries evaluated meet the standards established by the World Health Organization (WHO). In the city of São Paulo, air pollution has remained above that indicated by the WHO over the last 20 years, according to a report by the Institute of Energy and Environment (IEMA – 2022).

This poor air quality has a direct impact on people's health, according to data from the "Shared Streets" project, which also investigated the costs of air pollution, assessing the impacts of annual exposure to inhalable particulate matter and key health outcomes. Composed of very fine particles of solids or liquids, suspended in the air, the pollutant is highly harmful to health when it penetrates the respiratory system.

According to the research, in 2019, this exposure was responsible for the mortality of 181 children, 144 cases of low birth weight, 1,040 cases of premature births, in addition to 2,701 deaths in all age groups. The report identified that hospitalizations caused by poor air quality generated an expenditure of R$ 1.4 million for the public coffers.

"There are basically two sources of data: the Cetesb database, which tells us how much particulate matter was measured over the period, and the DATASUS data, which shows a series of types of diseases that are associated with this exposure to particulate matter," explained Frederico.

Six specific causes of death (chronic obstructive pulmonary disease, diabetes, lower respiratory tract infections, lung cancer, ischemic heart disease, and stroke) and adverse outcomes in children (prevalence of infant mortality, prevalence of low birth weight infants, and prevalence of prematurity) were considered. From the concentration-response equation, the proportion of cases related to exposure to the particular material was estimated.

Sustainable policies

Last month, the Senate approved the National Air Quality Policy, which aims to establish emission limits and monitor air quality throughout the national territory. Linked to the monitoring and control of emissions, strategies are needed to promote sustainable mobility that result in a fair distribution of shared public space and the consequent reduction of pollutants, as indicated by the study.

Based on simulations, the FGV Cidades researchers investigated how the shift to non-motorized modes of transportation would contribute in environmental terms. In scenarios in which hiking is prioritized, the reduction reaches 339 tons of CO2 per day. In the case of bicycles, the reductions are also significant, ranging between 139 and 237 tons.

Among some of the measures necessary for a more sustainable mobility, the Executive Summary of the project highlights the need to encourage non-motorized modes of transport, in addition to the expansion and improvement of sidewalks, "basic infrastructure for the transformation of public space and, simultaneously, respond to the urgent challenges of combating the climate crisis and adequate conditions for public health in the city".

"The municipal rotation could be gradually transformed into a congestion charge, in a similar way to the charge applied to individual passenger transport companies, and the resource from both charges could be used to subsidize policies to encourage mobility on foot. This combination of charging for the use of automobiles linked to the financing of more sustainable alternatives presents itself as the next step to be taken by São Paulo on the path towards the promotion of active mobility", defends an excerpt from the document.

To learn more about the Project, visit the website.