I can see diesel being less than a couple of percent of sales by 2025 easily and there may well be taxes that will make petrol and old diesels very expensive to own. Not to mention a ban on ICE cars all together in built up areas. Park and ride or electrc only will be the norm I expect. Judging by the pandemic where a lot of folk liked clean air it may well be that driving in towns will be socially unacceptable long before 2030 anyway. Public transport is going to have to get much better going forward, as well as cheap to keep the poorer members of society mobile, and not just in the big cities.