It's a common enough problem - you're planning a journey, and Google Maps pops up to let you know that the one road you're unable to avoid driving down is currently clogged up with horrendous traffic, adding an age on to your trip's timing.
Sometimes, though, you'll get there and find the road clear and flowing smoothly, with nothing to delay you at all. What gives? We all generally presume technical gremlins, a delayed reaction, or perhaps simply much better traffic than is normally the case at the given time of day.
Perhaps we should be more cynical, though, and worry that a renegade artist has been making a fool out of Google with a trailer full of GPS-tracking phones carted behind him to confuse its mapping service. That's what Simon Weckert has been up to recently, as his art piece 'Google Maps Hacks' shows.
Weckert's handcart has 99 phones in it, all with Google Maps open, and walking them around a city can let him track in real-time the change from a green road to a red one, and in turn the behavioural change in the real world as cars and drivers consequently avoid that route.
The explanation supplied by Weckert online suggests that he's interested in exploring the space between our perception of spaces through technology like Google Maps and the actual reality of those spaces away from said apps and services.
However, it's probably true to say that for many observers this will mostly just be an interesting window into how you can mess with services that feel untouchable, like Google Maps, simply by acting in a way no normal phone-user does - principally putting 98 other phones in a handcart behind them.