This is one of those ideas that sound good on paper but the way it's implemented will mean it's terrible for the common person.
It literally punishes people who buy fuel efficient cars and encourages people to buy ICE cars which weigh less than hybrids or electric cars.
Furthermore they will not implement a uniform per kilogram per kilometre prices. They will heavily discount commercial vehicles while shifting the cost almost entirely to you and me. The heavy trucks will do a thousand times more damage to the road while contributing less than you do.