GPS is making traffic congestion worse, as more people more rely on GPS to find their way home. GPS' routing algorithm is so repeatable that from a given point A to point B, it always gives the same route (note: recently some GPS devices introduced the "eco" mode, whose routing algorithm optimize for less fuel instead of less travel time. But it doesn't change the deterministic nature of GPS routing algorithm). Some time some people want to take a bit detour, knowing the local roads (rather than the highway that GPS suggested), which cars drive slower though, may have much less traffic which eventually may result in less travel time. But GPS always faithfully and promptly recalculate and suggest a new route leading back to the congested highway. I don't have the exact data but I believe that as the result of GPS recommending the same route to everybody, the worth of time and fuel wasted and the extra emission will add up huge.

Another problem of GPS always recommending the same route is that it deprives our opportunity to explore. The best way to know the area that I live is to see where there are what in my own eyes. Often times, when I drive passing a corner, I noticed a nice shop and remembered to pay a visit later; I noticed that there was a farmer's market on that street on Saturday morning; I noticed that there was a drive-through 24 hours Walgreens on that block; so on and so on. To me personally, such way (knowing my area by driving around) works better than Bing/Google maps, Yelp and yellow pages. Also, when I'm travelling in other cities, I have abundant time and I want to drive around to discover the things that I won't see if I just follow GPS' directions from A to B.

So for those two reasons, I think GPS should have the exploratory mode (or maybe "Surprise Me" would be a catchier name): instead of reliably always recommend the same route with the least travel time (or least fuel consumption), I hope I can switch my GPS into the exploratory mode, so that it adds some detours, as far as it only adds a couple minutes travel time or a couple miles distances. Better if the GPS can remember where I have been already recently, so that next time when it introduces the detour in exploratory mode, it takes me to the neighborhood where I haven't been to recently.

Such exploratory mode may also create a new monetization model: local business can pay the GPS/map providers so that the exploratory mode increases the odds to detour the driver to where that local business is.

In my opinion, such exploratory mode will be a good differentiator in today's market, not too hard to implement and increases profitability.