Restricting the volume of high-emitting vehicles roaming city streets carries many benefits, from clearing the air to quieting the urban din and beyond. Recognition of this simple fact has led to the proliferation of clean air zones, designated regions within a city where vehicles must meet strict pollution standards or pay a fee to operate within it. At last count, over 300 such areas had been established across Europe. In London, which boasts the largest ultra-low emissions zone in the world, a study has found a secondary benefit: Kids started walking and biking to school more.
and the study in question, here: Children’s Health in London and Luton (CHILL) cohort: a 12-month natural experimental study of the effects of the Ultra Low Emission Zone on children’s travel to school
Very Much this ^.
All fines do is force too poor to walk when they cannot afford the fine or other options. If that is the goal, free/cheap access to pools and sports centres as we had in the 70s was a better solution.
If the goal is to stop driving. Points on the licence. And providing practical alternatives.