Doesn't matter what kind of black magic you put into a tiny car, a big heavy SUV will destroy it in an impact and barely take a scratch. People buy big SUVs because they "feel safer", and they're going to keep doing that without some intervention. If I were a national regulator I would pass a law adding a pollution rating and a 3rd party danger rating to the vehicle registration plate.
Big cars for safety is a tragedy of the commons type affair with one caveat.
There will always be large trucks and some large cars so having a larger car is slightly safer (I assume).
But as the portion of large cars increases, small cars presumably become more unsafe and those drivers will start buying large cars. Then when nearly everyone has large cars, everyone is left back at square one or worse.
Their car doesn’t let them see over the average car anymore and neither do they give them a (somewhat selfish) size advantage in a collision.
True, the larger car probably has bigger crumple zones, but since cars are now larger and heavier it requires more crumple zone to stop one. And parking, fuel efficiency, road congestion and car prices are all worse.
It's an irrational "feel safer" though. Despite no legislated requirement for mixed size impact tests, enough have been done to see that tiny cars do surprisingly well. Whether the microscopic Smart Car against an max size old Volvo estate, or super mini against a Range Rover. They are categorically NOT destroyed in an impact with the SUV barely taking a scratch.
I mostly agree with the rest though. :) My solution would be to copy the Scandinavians with a yearly car tax derived from a combination of weight over say 500kg and emissions.
This is a myth. There have been massive improvements in safety design and some tiny cars do surprisingly well in some tests against old cars of any size - but modern SUVs are much safer than a modern tiny car, and improvements to the strength of the safety cage in large vehicles have offset the improvements in smaller vehicles. Relative vehicle weight is still the biggest predictor of occupant injury, and the types of impacts that kill occupants (small overlap and side impacts) favour higher ride heights. There is no trick engineering that can protect the occupant of a tiny car from a 2 ton SUV going through the side window. You can see this in the data for average death rates (https://www.iihs.org/ratings/driver-death-rates-by-make-and-...) - the death rate per million registered vehicle years for mini cars is more than double the rate of SUVs.
