general problems of the 2001 Oldsmobile Bravada

I was traveling on the highway at the posted 55mph speed limit when all of the sudden, the vehicle completely shut off. There was no power as if the ignition for the vehicle was completely turned off. With there being no power to the vehicle, I could only allow the momentum of the vehicle roll to the shoulder of the highway away from traffic. I had no use of turn signals or hazard signals. Once I was able to get over safely, I looked at the dashboard and cold only see the battery indicator light on, no other lights were illuminated. I turned the key to the off position, removed the key from the steering column, reinserted the key and tried to restart the vehicle. At first, none of the dash board lights would come on when I tried to restart the vehicle, I had to repeatedly turn the key back and forth and then the dashboard lights all came on, I was then able to restart the vehicle as normal and let the vehicle sit for a moment. I was able to drive the vehicle to a safe location off of the highway and back home. This was a very scary moment simply for the fact this occurred while I was driving at a very high speed and during traffic time. I also had my children in the vehicle. I am very concerned and would like to get a possible solution.