How does a GPS-based predictive cruise control system (e.g. Predictive Powertrain Control / I-See / EfficientCruise) optimize fuel efficiency when approaching the crest of a hill?

1. It anticipates the crest using 3D topographical map data, reduces throttle before reaching the top to prevent unnecessary acceleration, and allows the vehicle's momentum to carry it over the crest before using gravity on the descent
2. It accelerates to maximum speed right at the crest to jump the vehicle over the hill
3. It shifts down two gears at the top to increase engine RPM
4. It turns off the engine completely 500 meters before the crest