1990 Ford F-150

Unknown component(s) failure causes vehicle to stall at speed that vary, fuel supply is sufficient and battery good, no indication that stall is imminent. Varying time lapses allow restart and normal driving. Ammeter and temp gauges normal. Re-start may occur immediately or several hours. Online search reveal this to be common with F150 1990-1995. I drive Colorado state highways that often have no shoulder to stop on and 60 mph limit is rarely observed by speeding motorists along with following too closely or too fast for conditions which has caused great concern for safety with stalled vehicle in traffic lane. Nighttime hazards with deer, elk and no street or road lighting does not slow traffic in general. Slept in vehicle after incident last Saturday night barely off the road, tried re-starts often twice started then stalled and manually pushed truck back to shoulder that had space. Nearest populated area approx 40 miles.