Ok so I've been thinking of something.
Cars need to be build to wistand 120km/h+ and are therefore kind of heavy and polluting.
But, in cities, where you can't go over 30km/h, why could we not phase out the concept of cars, and replace them by bikes and electric bikes ?
For a huge city like, you would need to combine the metro system with distribution too, to make it easier to move stuff around. I'm not sure how well it scales but it could be used in some cities.