If petrol and diesel cars are replaced by electric cars then this will reduce tailpipe emissions, but not non-tailpipe emissions, which can still contribute significantly to air pollution, particularly for particulate matter. It will also reduce noise from engines, but not from tyres. Car infrastructure (roads and parking) takes up space that can be used in much better ways that are healthier for the population, for example by making it car-free public space or green space. This will also reduce heat-island effects.
Finally, many people do not get enough physical activity, partly due to the use of cars, which cause disease and premature mortality. A shift away from the car to public and active transport (walking and cycling) can facilitate an increase in physical activity and save thousands of lives. We urgently need a rethink of what we want our cities to be: detrimental to health or promoting health. A shift away from car-centric cities to more active and green cities is urgently needed to achieve the latter, and a ban on diesel and patrol cars is only a small step.