My wife gets cranky with me when I'm driving us somewhere in somewhat heavy traffic on unfamiliar roads and I stop talking to her or start giving her 'terse' answers. I tell her that I need to pay attention when I'm driving so that I don't get in a car accident, and then she'll often say something thinly guised as humour such as 'driving is hard'. At which point I will often point out that she has been in three bad car accidents, two of which resulted in more than one car having to be written off- and that I've got a spotless driving record (not strictly true, I was in one car accident- but I was t-boned by an idiot running a red light cause she was talking on a cell phone, so that wasn't my fault). The conversation usually breaks down at that point, cause she'll claim she was just 'teasing' me and I over reacted (and I probably did, and she might've been, but she was also trying to make a snarky comment and get away with it), at which point I just completely ignore until the traffic relaxes, I figure out where I am, or we arrive at our destination. Either way- my point was- even when I have a passenger who can see the road conditions, she doesn't always recognize that the road situation is getting (or is about to become) complicated and I need my full attention.