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How do cities face traffic-related air pollution?

Reducing the emissions generated by road traffic has become one of the main priorities of cities. The circulation of vehicles is one of the main sources of emission of polluting gases in cities such as Madrid, where traffic is “75% with respect to the rest of the sectors that emit within the municipality […], both for nitrogen oxides and for particles (PM2.5)” (Foundation for the Promotion of Industrial Innovation & ETSII UPM, 2017), a circumstance that is also repeated in other European capitals.

But what actions are local governments developing to solve traffic-related air pollution?

Solutions to combat traffic-related air pollution in the city

Stopping pollution in the city is a task that does not depend exclusively on public awareness. Other tasks should be taken into consideration, such as:

  • Encouraging the use of public transport and other alternative methods.
  • Adopting measures to reduce the use of private vehicles.
  • Using systems such as ENVIRA NanoEnvi EQ to carry out indicative measurements that complement the readings of the fixed stations and observing how air quality improves with the implementation of the different policies.
  • Sharing the progress with citizens, making them share in the results.

The following sections offer a more detailed view of how some of these solutions are being articulated.

Free public transport

Some European cities have begun to follow the wake of Tallinn (Estonia), offering their residents free public transport.

Although for the public this is a very attractive bet (a survey on mobility in Spain showed that 80% of those surveyed would travel by public transport if it was free) (1), the initiatives that have not been successful.

Although at the beginning they present hopeful data, such as the case of Dunkirk (France), in the long run, the financing problems end up making the solution unviable. In fact, and as Álvaro Nicolás from the City Council of Barcelona points out, “there is no such gratuity in any case. What is done is to shift the cost of operating the service, which is the part that is partially financed through tariffs, directly to some rate or tax that is charged”.

Low emission zones (LEZ)

Low emission zones are areas in which, in general, vehicles with higher emissions cannot enter.

This solution, implemented for the first time in Stockholm, has the support of two-thirds of Europeans, according to a survey carried out in 2018 by Ipsos for the Transport & Environment group (4).

It is a solution that has aroused great attention due to initiatives such as the LEZ and ULEZ areas of London and Central Madrid, the solution launched by Madrid City Council in 2018 and whose delimitation can be seen in the following map.

This measure establishes the following regulations in relation to road traffic:

➢ Free access: residents, people with reduced mobility and security and emergency services.

➢ Limited access, which considers exceptions, moratoriums, and schedules for some groups for their function or characteristics.

Limitations on the circulation of vehicles not included in any of the above categories are regulated by its environmental label, an adhesive tag that is placed on the windshield of the car and used to classify vehicles depending on the emission of pollutants into the environment (5). Except in Madrid, where its placement is mandatory since March 2019, its use in other cities where restrictions of temporary circulation due to high pollution are adopted is voluntary, as in the case of Barcelona.

In relation to the effects on air quality that the Central Madrid experience is offering, the initial results seem positive, with a comparative decrease in NO2 levels with respect to previous years (6).

Access toll to the urban center

An urban toll refers to the fare that is imposed to travel by car in certain areas of the city. It is a measure aimed at reducing traffic jams in the city but also contributes to improving aspects such as air quality and noise. In most cities, money collected from programs is usually spent on improving urban transport. In Spain, there is currently no city that has opted to adopt this measure, but in Europe there are several examples, being London and Stockholm two of the cities of reference. In the case of the London capital and since 4th April 2019, driving around its urban center requires paying £12.5 (14.5 euros).

Restricted access areas

Numerous cities and small towns have opted in recent years to pedestrianize or reorder large areas of their urban centers creating superblocks, thus reducing space for the car in favor of citizens, a measure that also has its reflection in the improvement of air quality. A practical example of this solution is Pontevedra. The model of urbanism that has been developing the city since 1999 and that puts the pedestrian before the car was recognized by the United Nations in 2014. In addition to facilitating travel on foot and in non-motorized vehicles, the city has managed to reduce its emissions by 60% In the city center.

Mobility as a service

What does a local administration need to offer to prevent citizens from using private vehicles as a means of transportation in the city? The city of Helsinki raised this question when it began to outline what the mobility of the future should look like (7).

The answer was mobility-as-a-service (MaaS). It consists of a digital service (a mobile application, for example) through which people can access a series of public transports, shared and private, using a system that integrates planning, booking, and payment of trips. By facilitating the use of public or alternative means of transport, it reduces the number of private vehicles that travel daily through the city, contributing to improve air quality.

Road traffic is, in short, one of the main sources of emissions in the city. Therefore, to improve air quality in urban areas, it is essential to reduce their presence. The solution, sensitizing, encouraging the use of public transport and developing coercive measures to convince the public that using the private vehicle in the city is the least intelligent option.

How do cities face traffic-related air pollution?

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