The Road Traffic Act, 1933 requires all drivers of mechanically propelled vehicles in public places to have at least third-party insurance, or to have obtained exemption – generally by depositing a (large) sum of money to the High Court as a guarantee against claims. In 1933, this figure was set at £15,000. The Road Traffic Act, 1961 (which is currently in force) repealed the 1933 act but replaced these sections with functionally identical sections.
Auto insurance is financial protection, and not just for the investment you made when you bought your car. After a really serious accident, bills for damage and injuries can easily reach into hundreds of thousands of dollars. If you happen to cause such a wreck, the victims could sue you. In the worst case scenario, assets such as your savings and home could be seized.