This comes up every month or so, and the responses are the same. I've seen some crazy routing as well. It was especially bad going through the DC area, but it's bad in NJ too. It has some strange logic. I'm actually impressed when it chooses an efficient route. I've had nav equipped cars since 2004, and even compared to the poor MB COMAND system, this one is the worst.
Mine also contradicts itself. The voice will say one thing, but the screen shows another. And if you have HUD, you need to cancel the guidance before you arrive at your destination, or it will keep showing the directional arrows until the car is shut off.
ED on 7/18/2014: 2014 550i, Space Gray, Mocha. M Sport, Cold Weather, DAP, Executive, Lighting
PCD on 9/6/2011: 2011 550i, DSB, black/oyster. Prem 2, Conv, Ventilated, HUD, Sport, DHP, SAT