Well I don't know why the US is so behind in terms of car insurance, but here in the UK

1. If you are the registered keeper of a vehicle, then you pay car tax or give a "Statutory off-road notice" ("SORN"). If you fail to do one or the other there is an automatic fine as such.

2. If you have not given SORN then it is a crime not to have insurance - and again there is an automatic fine as such.

3. It is also an offence to drive or keep on such land a vehicle without tax (except to go to a pre-booked MoT test, see below) or insurance (or a driving licence)

4. If the vehicle is over 3 years old it is further an offence to drive or keep it on such land without a valid test certificate (usually called an MoT).

This is in the interest of public safety and government economy. It costs less to enforce than relying on catching a miscreant on a public road, and it makes it harder for unlicensed uninsured drivers to use dangerous vehicles. Public opinion seems largely to be in favour of even more stringent measures.