The ground breaking part is not the tunnel but the vehicles. Its extremely dangerous to use ICE vehicles in long tunnels without complex ventilation schemes. Electric vehicles solve this issue.
True, however that requirements are more relaxed. The invention of electric train removed most of the problems with coal based (and other vehicles and helped in creation of subways).I think the movement to electric will create the same oppurtunity for cars.
>The ground breaking part is not the tunnel but the vehicles.
Underground LRT (aka "a subway") are electric vehicles that travel in tunnels. In what sense is replacing a subway with an electric car that runs on rails "ground-breaking"?
The initial idea was to have tunnels for cars, however since most cars on roads are ICEs, the cars on rails was brought about as an alternative. In an ideal world with 100% electric vehicles, the complete transportation can be moved underground and the cities can appear as natural as possible.
Tires seem to be completly another beast. Apparently, most of the pollution from tires are usually stuck to the roads and are washed periodically with water and soap [1]. I am not sure how much tires contribute to air pollution.
Sounds like it's more so water pollution where tires are bad:
> Driving is not just an air pollution and climate change problem — turns out, it just might be the largest contributor of microplastics in California coastal waters. [...] Rainfall washes more than 7 trillion pieces of microplastics, much of it tire particles left behind on streets, into San Francisco Bay each year — an amount 300 times greater than what comes from microfibers washing off polyester clothes, microbeads from beauty products and the many other plastics washing down our sinks and sewers.
