[mopeloi]

So, is this picking up on large landmarks which are visible in StreetView? Sun position in imagery? In Manhattan can it see a sign reading W 53rd St and know whether to go north or south to its destination? The paper suggests that there are learned landmarks, but doesn't talk about street signs at all. As a New Yorker, that would be the first method I would use to reach a destination.

[curiousgal]

It's a neural network so chances are, we'll never know how it came up with it's decision. For CNNs we can look at the output of each layers to get a hint but the more diverse the architecture is (such as in this example) the harder that becomes.