obligatory insurance

基本解释

First part is the generalization of the motor vehicle traffic accident obligatory insurance system.
第一部分为机动车交通事故强制保险制度概说。

Meanwhile, although federal flood insurance was both subsidised and supposedly obligatory for most mortgage holders, remarkably few people on the Gulf had federal cover: less than a fifth along Mississippi's coast and only 40% in New Orleans.
ECONOMIST: Hurricane Katrina
An alternative would be to make natural-disaster insurance (covering floods, earthquakes, avalanches and so on) obligatory, with premiums more closely reflecting the risk.
ECONOMIST: Hurricane Katrina