Continuing my intermittent series of 'possibly interesting things I saw on Google Maps', here's a question - what's the limit of the 'directions' feature?
For example, can you get driving directions from any place in the world to any other place in the world, as long as both places are on the same land mass? Spoiler: no.
Let's go driving
I was recently trying to plot a route around the world for an unrelated project. GMaps seemed like a good place to start, but I figured I'd need to break the journey down into at least two legs to give it a start and end point that wasn't the same place. My starting point was London, so I randomly chose Beijing as the destination. It didn't work.
Sorry, we could not calculate driving directions from "Beijing, China" to "London, UK"
Curious, I aimed for somewhere a bit closer - Hanoi, Vietnam. Turns out you can't get driving directions there either, but it is possible to get walking directions (a journey of 12,298km, estimated to take 2,505 hours, including a ferry. The route "may cross country borders", apparently).
(important note - for almost all of the routes I'm trying here a flight option is available, but I wasn't interested in that as it doesn't show the distance involved)
We'll come back to China in a moment, but let's ask this question first: is there really no set of roads that connects London and Hanoi, or does GMaps simply lack that data? It seems likely that there is a road, but if GMaps doesn't have that data, how does it have data for walking?
Let's try breaking down the route into smaller chunks; perhaps GMaps can't calculate over such a distance. Here we go.
- London to Baghdad - driving route possible
- Baghdad to Karachi - driving route possible
- Karachi to anywhere in India - driving route not possible
It seems like the India/Pakistan border is the problem. Every route I tried failed to produce driving directions, even between Lahore in Pakistan and Amritsar in India - two reasonably large towns either side of the border separated by only around 60km. Weirdly, they appear to be connected by a single straight road that crosses the border through which GMaps suggests a walking route, but nothing else. My knowledge of the geo-political situation in that part of the world isn't great, but a quick read online suggests that transport links of some kind exist between the two countries.
But let's get back to our original problem. In order to drive to Vietnam from London without crossing the India/Pakistan border you would have to drive through China, which was what I was trying to do in the first place. Let's try some more tests.
- Beijing to Hanoi - no driving route
- Beijing to Ulan Bator - no driving route
- Beijing to Kabul - no driving route
- Beijing to Kathmandu - no driving route
It seems that there is no driving route that GMaps will give for anything into or out of China. It's worth noting that there seems to be nothing wrong with directions within China itself - driving, trains and walking all worked fine for every direction test within the country I tried. What's going on? Is the Great Firewall really that powerful? For whatever reason this just doesn't seem to be possible.
Roads? Where we're going, we don't need roads
That got me thinking. Where else in the world is it not possible to get directions to? Here are some more directions routes that aren't possible, starting with an obvious test...
- Pyongyang to Seoul - no route of any kind available
- Pyongyang to Moscow - no route other than flying
- New York to Buenos Aires - no route other than flying
That last one was a surprise, considering that I'm not aware of any problem Argentina has with the US and I'm pretty sure there's a massive highway running all the way down from north to south America (the Pan American highway, no less). Let's try breaking it down again.
- New York to Guatemala - driving route possible
- Guatemala to San Jose, Costa Rica - driving route possible
- San Jose to Panama City - driving route possible
- Panama City to Bogota, Columbia - no route other than flying
The problem seems to be something between Panama and Columbia. A quick search online reveals the details - The Darien Gap, a 160km long break in the Pan American highway consisting of swamp and forest. Apparently it has been crossed in the past, but is now considered too dangerous, partly due to the presence of rebel groups. If you can make it to Bogota by some other means, a driving route is then possible all the way to Buenos Aires.
Is there anywhere else? Here's one. How far east can you drive in Russia? Again, attempting driving directions, starting from London, I've got as far as a place called Ust-Nera, but getting any further seems problematic. It seems more likely that navigation in this instance is hindered by physical terrain rather than political problems.
If you want a quick and lazy way to plot a driving route around the world, Google Maps may not be the solution. Whether it's entirely sensible geographical obstacles, political or military boundaries, or simply unanswered weirdness, some routes are simply not possible.
Finally, I was a little sad to discover that GMaps no longer seems to offer a route between London and Paris that includes directions to the coast followed by the instruction "start swimming" (as it did some years ago). I can't even get the 'the Shire to Mordor' easter egg to work either. What's going on, Google? Did you get all serious on us?