This problem has occurred 3 times in the last 3 years. The car has barely been driven with less than 15k miles as of this date. It has occurred on each occasion after driving for 3-4 hours at freeway speeds. After stopping for a rest stop break the engine stalls during acceleration back onto the freeway always along a tightly curved on-ramp. Aside from the obvious surprise and concern, cars immediately following had to panic stop to avoid our vehicle as I attempted to negotiate it onto the adjacent emergency lane with impaired steering and brakes. After stopping I turned the ignition to off then re-started the car and was able to proceed. Of the 3 times so far the conditions under which it occurs have been nearly identical.