Researchers at the Barcelona Supercomputing Center-National Supercomputing Center (BSC) have concluded that the traffic restrictions applied in Barcelona are “insufficient” to comply with European air quality legislation. The center has reported in a statement that, according to the study, an “optimistic” renewal of the vehicle fleet and the 25% traffic reduction expected by the city council by 2024 it would reduce the concentration of nitrogen dioxide by between 20 and 30%, depending on the street.
The study also shows that, when only measures are implemented that reduce the space available for private transport, such as superblocks or tactical urbanism, changes in nitrogen oxide emissions are “negligible”, since the measures have a rebound effect – in his expression – in the confronting areas. These restrictions generate a redistribution of traffic along the network and, therefore, a redistribution of emissions at street level, with nitrogen oxide variations of up to 17% on specific streets where vehicles pass more now .
The municipal forecast would be “barely enough” to meet the annual average for this substance regulated by the European Union, of 40 micrograms per cubic meter of air. In addition, the WHO reduced its recommendation for this limit to 10 micrograms, “which represents an even greater challenge for the city.” “Without this significant reduction in traffic, the impact of the Low Emission Zone and the implementation of measures such as superblocks or tactical urban planning is far from the objectives set by the European Commission”, resolved the BSC. Therefore, “the measures adopted so far must be complemented with new traffic restrictions to improve air quality in Barcelona and keep the concentration of pollutants at acceptable values for health “.