I visited my in-laws in Pennsylvania over the weekend, and used my nav, as I always do, for turn reminders in case I zone out. My factory nav system always sent me the same way - I-81 to US-15 to I-70 to I-270 to I-95. The NEX sent me that way as well when I was up in June. This time, though, it sent me I-81 to I-83 to I-695 - a route that's farther by 20 miles, with worse traffic because it catches I-95 in Baltimore and takes I-495 around Washington to the east (through Greenbelt and Alexandria) instead of the west.

What gives? The start and destination points were exactly the same, and I haven't installed any firmware or map updates. I guess it could be because of traffic on I-70 or I-270, but I don't think information for that area was available when I was at the point that the routes diverge (Harrisburg).

You probably have traffic monitoring turned on, and well the monitoring doesn't work well, and still sees light traffic and tries to send you around it. Turn off traffic and see how the routes are then.

OK, that makes sense. It is very sensitive to traffic - for example, it tries to take me off I-85 thanks to non-existent construction-related traffic around my mom's house every single time.

The rerouting it did on I-95 was maddening, too. Get off 95 (which is stopped, so good idea there), get on US-1. Drive 3 or 4 miles on US-1, get back on 95 (which is still stopped), go to the next exit, get back on US-1, lather, rinse, repeat. I eventually just ignored it and stayed on US-1 until I saw in the itinerary that it wasn't going to try to take me off 95 again once I got back on.

It does make me wonder what the range for traffic info received via FM is. Like, when I'm in Scranton or Harrisburg, how far does it extend? Baltimore? DC? Richmond? Farther?

This is where it would be nice to have something like AVICSYNC that pulls current data from Waze.

It's suppose to differentiate light, heavy, moderate traffic, but from experience it does not.

Well, in this case the traffic seemed to be either "no one else within 100 miles" or "escape from a large city during a zombie outbreak" with no middle ground that day.

Yes the traffic routing is horrible. It once had me take the wrong freeway, get off after a mile, and turn around and merge back onto the right freeway thinking that would avoid some light traffic. 

Agreed. Guidance is terrible. I decided to give the navi one more chance after the 1.06 update. I usually turn on the back to gauge my eta to home. Like a dummy, I decided to follow it instead of my usual route. Well it took me to heavier traffic and extend my drive by 10miles and 30minutes. Like I've said in another topic here, the Z130 did a lot better along with remember the turns I usually make. Feels like I downgraded just to get some features that I thought would be upgrades. Turns out there are plenty of issues on the firmware making the NEX models sub-par compared to the AVIC Z models.

I've had similar issues with the 8000NEX GPS.  On several trips it suddenly deviates from the initial calculated route (gps voice stating "recalculating") often taking me miles out of the way or off of highways to drive through busy urban streets.

I'm ready to go back to my portable Magellan gps.

I was really excited to have the traffic feature built into the head unit, but after noticing the exact same problem in Nashville on my daily commute. I decided to turn it off.