I had just come of the highway and stop at traffic light and my car just quit. I was able to start the car and drive on. I have had this problems a few times, but can't get this condition to be consistant. I also had the car cut out at 70 miles on highway. Any suggestion what it could ?

Could be many things but usually turns out to be electrical. I had a similar issue some time back, turned out to be a very slight leak in the sunroom which had corroded the connection for the fog light switch. Every so often it would short and the engine would die. Fairly easy fix there but electrical issues can be a pain to find.

Look for anything acting funny. Does one headlight flicker? One dimmer than the other? Tail lights, stereo wires, and almost anything carrying 12v from the battery can cause issues. I've even seen slightly loose battery cables cause the same issue. It might be tough to find, and you probably won't find it just glancing at the lights, but keep an eye out for these things.

Well believe this or not.....My 94 bonnie would also die whenever it wanted to. You could always start it up by putting in neutral and re-starting. Sometimes before it would die it would have an increase in rpms and then sputter and die.

Put in a new ignition module, checked just about everything I could and it still would die any time it pleased.

The exhaust connection between the output of the catalytic converter and the exhaust pipe had a leak and it was getting louder. So one day I had a shop re-weld it ( that took some talking to get that done vs a new system).

Now I did this to stop the leak, its been about 3 months and the car has never die in the last 3 months. Could they be related, I have no idea but I'm a happy camper.

Some day I'll tell you my story about the same 94 bonnie and its ability to gobble up alternators at will.

If you have a multimeter, check resistance from the engine block to the frame. It should be relatively low (less than 5 ohms). If it's higher, you may have a bad engine to chassis ground strap, which will cause all kinds of electrical anomalies. This is a common problem on 92-95 Bonnevilles.