ummmm... GPS much? I would think an updated Garmin NUVI would be a much better idea than a smartphone, if you're going to be "getting away from it all" for awhile.
Also keep in mind that any GPS is going to fail where the source material (road information) is inaccurate. There are numerous "horror stories" about people placing too much "blind faith" in their GPS.
The most glaring (and probably least credible) example I can think of is where a gps said to someone "TURN LEFT" and they immediately did, running off the road.
More practical and better documented examples exist of people trying to use a GPS to drive them through the desert and turning off a highway onto side "dirt roads" and driving until they got their grocery-getter stuck in the sand dozens of miles from civilization, with no cell phone reception, no supplies, and no one notified of their travel plans. Deserts are well-known for this GPS problem, and some counties even post signs warning people of the dangers of following their GPS blindly, as well as the important need to notify others of your travel plans, packing supplies in case of breakdown, and avoiding unmaintained roads. Those signs are there because those sorts of mistakes have proven fatal or nearly-fatal on numerous occasions.
I've also read of numerous examples of GPS maps thinking a road goes through when it does not, even with updated maps. I have that issue right here in town, it tries to steer me through residential roads to get onto an expressway when there is NO entrance and I come to barricaded dead-ends with the expressway in sight on the other side of a ditch. I have to endure several minutes of "please turn around" as I know where the actual entrances are, before it finally switches to the correct route. (there are three nearby roads that ALL are marked as intersecting the expressway, none of which actually do, so it keeps trying to take me to the next one when I move on)
There's a more famous example of that in Nevada iirc, there's a long access road that almost connects two roads at a T, and almost every GPS tries to direct traffic down it instead of taking the exchange ahead. The road is long, and finally dead-ends with NO turnaround. Because this sucks in 18-wheelers as often as several per day, requiring them to BACK UP OVER A MILE, they've posted massive signs at the exit to the road, saying "THIS EXIT DOES NOT CONNECT TO XXX, YOUR GPS IS **WRONG**, CONTINUE TO NEXT EXIT". This had been going on for almost a year, and despite many complaints to the GPS vendors, the mistake had remained on the new updates.
The lesson then is "verify the route with google maps and VISUALLY trace the proposed route prior to taking it". Make adjustments if needed. You may have to make a travel sequence with waypoints to force your GPS to not take you down stupid routes. I think your described road trip could have used better planning the day before embarking on each leg of your journey.
Side-rant... I wish my GPS had the ability to select a segment of road and temporarily mark it "impassible". When I get a closed road, road construction, bridge out, etc, it can be quite a struggle sometimes to force my gps to find "the next best route". We had a rural bridge get taken out in a flood a few years ago here, and good lord, my gps would NOT give up on that bridge ("please turn around!") until I got almost two miles from it. "You are NOT HELPING here!" I ended up doing quite a bit of zigzagging through the roadways that hugged the river (when I was nowhere near a bridge) until it finally routed me to another bridge. The next time I had to take that route, I realized what it was trying to do and got on the GPS's preview, and set a waypoint at the bridge to the east now that I knew where it was, and things went much smoother. It would have greatly simplified things if I could have just moved the arrow to the little segment over the water, clicked, and marked IMPASSIBLE and triggered it to automatically reroute me, until which time I removed that mark. My newer Nuvi has a "detour" button I can hit anyway, that shuts it up about turning around, but it still relies on me to find my way around the road closed / detour, at which point it recalculates and gets me back on track.
and total segway... map making is expensive and time-consuming, and companies are deeply tempted to copy their competitor's maps instead of licensing them. For this reason, map makers sometimes leave a deliberate error in their map (a grid of roads, where a single segment does not go through, they will leave that segment in) so if someone copies their map, they have a case to prove it. I'd imagine there's a name for those 'telling blems' but I don't know what it is. I wonder how many gps mistakes are due to that?
