There's very little cost for the inclusion of an AM detector into a radio set. And low-frequency AM radio tends to have far better area coverage than the FM sta

There's very little cost for the inclusion of an AM detector into a radio set. And low-frequency AM radio tends to have far better area coverage than the FM stations do with their use of VHF 'line-of-sight' frequencies. That's just what's necessary in emergency situations, like tropical storms or wars.