The main problem I see with that is detail and the age of your data.
Drawing from experience trying to memorize a journey through the city of Bale, which whilst less large than London is quite winding and certainly suffers from the same compounding of historical and modern buildings. Going through my route, spots where i stopped to take in more details are very much more tangible in my mind. The wide park circled by a walkway where I stopped for a short break is quite vivid in my memory, and I can pull dozens and dozens of points from it. The path along the viaduktstraße leading up to it is far more faint in my memory, considering I only remember the Paulskirche and one of the bridges towards it. Considering only something akin to Google Streetview would be practical, there seems to be just to few points your mind can latch onto to create a detailed image of the location. In addition to that, your other senses do play a significant role in remembering locations.
Also, cab drivers need to know very recent information you're tempted to overlook designing a game like that. How fast does traffic go at this time of day at this location? Are they setting up construction over here? It's often not even realized consciously, but rather factors into decisions on a lower level, turning into the "hunch" you have about a certain route or even more generally a certain course of action.
So unless there is a way to have a perfect representation of the city that is also less than a day or two old, it's not really a replacement for actually going through those streets.
Does the test check the best way, or only knowledge of finding Some route? I could see someone learning the city topology with VR, and then using experience to learn congestion patterns.
Drawing from experience trying to memorize a journey through the city of Bale, which whilst less large than London is quite winding and certainly suffers from the same compounding of historical and modern buildings. Going through my route, spots where i stopped to take in more details are very much more tangible in my mind. The wide park circled by a walkway where I stopped for a short break is quite vivid in my memory, and I can pull dozens and dozens of points from it. The path along the viaduktstraße leading up to it is far more faint in my memory, considering I only remember the Paulskirche and one of the bridges towards it. Considering only something akin to Google Streetview would be practical, there seems to be just to few points your mind can latch onto to create a detailed image of the location. In addition to that, your other senses do play a significant role in remembering locations.
Also, cab drivers need to know very recent information you're tempted to overlook designing a game like that. How fast does traffic go at this time of day at this location? Are they setting up construction over here? It's often not even realized consciously, but rather factors into decisions on a lower level, turning into the "hunch" you have about a certain route or even more generally a certain course of action.
So unless there is a way to have a perfect representation of the city that is also less than a day or two old, it's not really a replacement for actually going through those streets.