We were accompanied on our travels by a Satnav system with a friendly female voice, who my daughters promptly nicknamed Tammy. Once our destination was entered, the screen showed that we had to turn left in about 200 kilometres, so it was straight up the east coast of the island.
Tammy was all you could want in a best friend and guide. Always calm, she told us "in 200 metres turn left", and then as the turn approached "turn left". But if we made a mistake, she never berated us. Instead, she recalculated, and either told us to "turn when possible" or found a different route for us. Never a regret about past actions - just "how do we get there from here?" Even when we confused her by diverting from our route to find a restroom, or a KFC store.
Once in a while, though, Tammy was wrong, and we had to trust our instincts. According to Tammy, this is not a road (her screen showed us driving across country):
(It was too new to show on her map).
On the other hand, Tammy thinks this is a road:
This is the vehicle ferry across Cook Strait, which shows as a toll road. Just out of curiosity, we asked for an alternative route with no tolls, but she failed to find one. She must have failed to consult these men who sailed their van across, perhaps inspired by Top Gear
Tammy does not think this is a road:
but in fact both are legal highways. The first photo is of Ninety Mile Beach, which is actually only 55 miles long -still by far New Zealand's longest beach. We drove up it after a careful check of the tides. The Satnav screen showed us surrounded by water, and after a while Tammy stopped saying "turn when possible" and merely showed a dotted red line connecting us across country with the nearest road she could find. Tourist buses take this route every day, but there are signs warning cars they proceed at their own risk. But my husband is a confident driver, and we made it with no problems after a careful check of the tides. In fact, we drove too far up the beach having missed the turn off up the stream, and asked directions from a friendly fisherman. The second photo shows the route off the beach up the Te Paki Stream. You can see the tyre tracks we were following disappearing into the water (shallow, fortunately). It's the only place I've ever seen a road sign which says "Caution Increase Speed". (To avoid getting stuck in the sand). Then, near the top where you emerge onto a properly formed road, there is a sign sticking out of the stream which warns "Caution Oncoming Traffic" which made the girls crack up with laughter.