Not to be snarky, but can’t you tell that on your own?
I don’t know that much about GPS maps or software, but if they’re anything like other map software I’ve used, I definitely don’t trust them.
There was one where I looked up my address at the time, and the map had my road mislabeled and another road that didn’t exist running parallel.
The worst was a version of MapPoint. I was trying to get an estimate of distance and time to a destination I was very familiar with. The stupid software took me past the exit I needed, south for about 50 miles, then it turned off the highway and on to county roads to bring me back 50 miles north to where I was headed. 
I was able to force it to take the route I wanted, so I got the info I needed, but for the life of me, I don’t know what the heck it was doing.
Anyway, because of those experiences, I prefer to know where I’m going before I leave, and when the GPS agrees with me, I’m happy.
Giggles; everytime I read this thread title…
When driving to the train station parking lot at Mt Washington, my Garmin Nuvi threw a tantrum. “Recalculating…! Recalculating…! Please Drive to Highlighted Route!!!”
The ‘highlighted route’ being the car road on the other side of the mountain. But it said it in such a panicked voice, I swear I thought it was next going to say, “Aunty Em…! Aunty Em…! We can’t Find you Aunty Em…!” :rolleyes:
Then again, I guess we’re all lucky that it doesn’t say, “Recalculating! In 100 yards, swing seat beh-elt over head and cluck like chi-cken…”
Turn the GPS off, unless you need specific directions to a well known location, like a hotel. Using them to drive has got several people stranded and even dead. The maps are all a continual work-in-progress, a lot of the info is just wrong.
I live on a short road at the base of several hundred square miles of forested mountains. But the GPS says the little road is actually the logging main line that heads up into the forest. It is amusing to watch the FedEx van go barreling up the logging road into the wilderness, driving by GPS instructions. They usually figure out after several miles that there are no houses up there and turn around.
My wife and I got a Garmin as a Christmas gift last year, but never really had much of a reason to use it until our trip to Southern California back in August. One thing that my wife noticed was that if she was zoomed in too close, it would not tell us to turn until we were already through the intersection or past the ramp - too late to do anything, obviously, and then it would recalculate. She finally figured out that if she zoomed out a click or two, then it would give us fair warning when we needed to turn.
They can’t be trusted. I had DeLorme software tell me to get on the freeway going the wrong way, then turn around at the next exit. When I didn’t do that, it wanted me to make 2 u-turns to get back on track. Later on that trip it had me turn off the highway onto the wrong end of a road that looped back to the highway. It’s routing algorithm seemed to be “always turn as soon as possible”
A usually superior Garmin unit still sent me down a 2-track 4WD road. Since I happend to be driving a 4WD, I stuck it out just to see if it actually did get me there…and it did!
Google maps routinely pisses me off with it’s inability to sensibly construct a looping route…even with lots of waypoints it always wants you to backtrack at some point. It is enough of an issue that they have menu choices that look like they are intended to help the software, but they still fail for me. Fortunately I am usually doing this after the fact to see how long a bicycle ride was when I didn’t note or reset the odometer at the start. I would be livid if I were actually trying to use that crap to navigate. Also they used some sort of automated capture for bike paths, which often fails when the path crosses under a street.
I’ve used Google Maps to plot out stuff and have also found U-turns in their online directions. Usually in some really odd routes (like I came up with walking directions from here to Arizona just for fun - several Uturns there).
As an aside, I sure wish Google would update its Android navigation app to be able to work from a preloaded route. I might need to go to 2 or 3 places, or need to take a specific route that the navigation app wouldn’t send me, and while I can send myself the link and bring it up on the phone, I can’t make it narrate me through the driving. Annoying.