This happened to me three times now while driving on interstate highway at 65 to 70 miles per hour. Very scary and dangerous when it is so dark you can't see to pull off the highway. After about 1 hour or so into my trip the headlights turn off ,then flash on and off a couple times before correcting themselves and usually stay on the rest of trip? I replaced the headlight switch last week thinking that was the problem, but it occurred again last night. Problem has not occurred on shorter night drives of 1/2 hour or so.