How do I get (wherever)?

[Crosley]

Some times the map software is just wrong  ... I used my Garmin 2610 to find our son's house in Smyrna TN on our first trip to visit him there...

So .......  as we sat next to an open dirt field, I called my son. 

After the laughter settled down , he told me to turn around and drive back up the road.  He said the map software on Mapquest and others showed his house in the middle of that field.

[relaxedphit]

Being with NCDOT Location & Surveys, we have quite a few bridge replacement jobs on some fairly obscure county roads. Sometimes my Nuvi seems to know nothing about a road until I'm(it) is in the county. I'm a surveyor with a poor sense of direction--kinda like a chef without taste buds. I've gotten some bizarre directions from Mapquest and was told (the value of free information)  that it was designed to take one past as many McDonalds as possible.

[Tzoom]

I used my Magellan Roadmate 1430 to go to Kansas last weekend.  The unit got me to the front door of every address I entered.  But every time I've used it for return trips home it shows that I live a block west of my house.  Go figure. 

[Seldom Seen Slim]

I've had both GPS units do sort of the same thing.  When I enter 509 Dukes Road -- the units will have me go about a half-mile up the road from the house (our addy is 509 Dukes).  So I looked around and found a button that let me set "this location" as home.  Click while in the driveway -- no more mistakes.  Funny, though, how the machines both had us out in the woods near home. . .

New query:  How do I change the pre-set speed that's used to figure driving time to destination?  I don't think the unit is learning from our driving -- seems to think we average 62 or so, and that's quite a bit above our true average.  I'd like to get the correct number in there so I'd get more accurate estimates.  The unit is the Garmin Nuvi.