"Turn around when possible." … "Turn around when possible." … "Turn around when possible."
I love my TomTom. SatNavs in general must be among the most rapidly-adopted consumer electronics innovations. The best are not bad when it comes to usability either, but I suspect their rapid adoption is down to something that trumps ease-of-use when it comes to consumer interest – good old fashioned value. I don't mean price (although prices have tumbled, and you can't complain when you can buy a basic model for less than the price of a tank of fuel). What I mean is user-value; what it does for you. Never get lost again, and never have to read a map. That's some offer, and it's no wonder that the first workable technology to deliver on those promises has pretty much cleaned up in the market.
But that's not to say they're without niggles when it comes to usability, and I'd like to share a couple of my pet peeves.
The first is the above. "Turn around when possible." Sometimes it just isn't possible or, for whatever reason (a fear of reverse-gear perhaps), I just don't want to turn around. Sometimes I want you (Mr or Ms SatNav), to take me to my destination without my having to execute a three-point-turn on this busy road. That being so, when you've said "Turn around when possible" three times in a row, why don't you just shut-up, and re-plan my route in whatever way works best if we keep going straight ahead. You're asking me to turn around. I'm not doing it. You know I'm not doing it. So why don't you take the hint?
My second peeve is about diversions. When I come across a road-block, I usually need to decide what to do now. Do I leave the motorway? Do I go left or right at the roundabout? Quick! What I don't need to do is to drill down three or more levels of options (menu > route options > find alternative > avoid roadblock > 1/4 mile roadblock) before I can tell you that I need your help. I need to be able to hit one button, from the homescreen ideally (although I accept that space is at a premium there), and say to you, "I'm going off-piste. Tell me quickly which way to turn so I avoid the next bit of the route but keep travelling vaguely towards my destination. Then we'll talk about the details later." And don't tell me it would take too long to replan the route at such short notice. What are you doing whilst we're driving along? Why don't you keep a backup route in mind all the time, so that if I suddenly tell you the way ahead is blocked you can instantly swap me onto plan B?
Both of these things speak to a lack of understanding of the user's world. They both represent failures to understand that the user might just have a better idea of what's going on in the real-world than the machine, and that the machine could take advantage of that extra information if only it bothered to listen. A real human navigator in the passenger seat would do exactly that (well, depending on who it was, obviously). So at these moments of failure the spell is broken, and the mental model of a nice helpful person inside the box is replaced with the reality of how it really works – a pile of dumb software. The result is frustration on the part of the user, and a squandering of the emotional appeal and attachment that he or she has for the product.
SatNavs, perhaps because they replace a human role, and especially because they speak, are very likely to present this anthropomorphic mental model to their users. And in this case, that feels appropriate. But in most products it's a high-risk strategy, because the only thing thing that's more annoying than being ignored by a fellow human, is being ignored by a lowly machine. It really puts you in your place.