And I'm certainly not thankful for the driver to have taken all this effort of solving the difficult problem of going somewhere that he doesn't know the road; I'm angry about the large unnecessary delay caused by them saying "yes" and then being unable to properly fulfil the promise they made, i.e. go to the goal as if they had known where it is, which they said (thus, promised) they do, and didn't. I wasn't asking "are you willing to take extra effort to deliver me to place X in some way" (which is a reasonable question that I might have asked in some circumstances, but I didn't in that particular case), I was asking "do you know the route to place X". I would be thankful if they had just said "no", as I would have had the chance to find someone who does know the proper answer themselves.

This is a significant cultural difference - in my country, answering yes when if you're not sure (and demonstrating the lie by being unable to fulfil the promise on their own) would result in that person's words not being respected anymore because that person isn't honest, and that person being shunned, not being trusted with anything serious ever again until they prove that they have changed significantly; a single incident being considered sufficient to mark the person as untrustworthy. Breaking a promise or telling a falsehood - even an implied one to a stranger - is considered a very serious issue. The problem with this when working with people in Asia is that within a few months a majority of Asian coworkers generally have had at least one incident similar to this (saying, i.e. promising something that wasn't so) marking them as untrustworthy. Of course, as with any difference, it's an open question which one of the cultures should adapt to the other, or meet in the middle, but that's a quite fundamental difference.