♦ Travel insurance offers travelers coverage for unforeseen problems, from a cancelled flight to a serious illness—or in rare cases, even an act of terrorism or the financial default of a travel supplier. If an illness, accident, or other covered unforeseen circumstance forces a traveler to cancel or interrupt their travel plans, they face two potentially major financial losses—money invested in nonrefundable pre-payments and medical expenses that in many instances may not be covered by health insurance.