In 2008 CNET UK pitted a London cab driver against a driver equipped with TomTom 520 satellite navigation device (the Brits call them ‘sat-navs;’ we Americans call them GPSs, for ‘global positioning systems’). The cabbie won handily.
In 2010 Prof. Chris Bishop of the University of Edinburgh and Microsoft Research Cambridge tried again, using a more advanced sat-nav. He didn’t specify the model, but said that it had access to real-time traffic information and a database of previous journeys. No matter; the cabbie again crushed him in a cross-London journey.
There are two main reasons for these lopsided results. The first is that London cab drivers are extraordinarily well informed and deeply trained. Since 1865 all licensed black cab drivers have had to pass a test, appropriately called ‘the Knowledge,’ of the city’s streets and traffic. As the Transport for London website explains, “drivers’ Knowledge is based on learning 320 routes (or runs). This will help them learn the 25,000 streets and 20,000 landmarks and places of interest in the six mile radius of Charing Cross.” The average student requires about three and a half years of dedicated study to acquire this much knowledge, and a dozen attempts at a test administered by the city to demonstrate it.
The second is that the sat-navs were pretty bad at actually navigating. Both videos make it clear that the devices told the drivers to go the wrong way down a one-way street, turn onto a road that had been barricaded, and/or proceed down a road that had been closed for construction. Their maps, in short, didn’t line up well with the actual roads and road conditions of the city. The cabbies presumably had a closer match, and so were much quicker than the devices.
I’ve been using Waze for a few weeks now (thanks to a tip from MIT Sloan doctoral student Matt Beane), and am wondering how much longer that will be the case in London (to say nothing of other cities where the professional drivers don’t have such deep expertise). Waze is a crowdsourced GPS app for smartphones; its now 20 million users transmit (anonymized) location and speed data as they drive around with the app active. This allows the company to build a real-time map of traffic conditions, which in turn enables dynamic routing. If I93 South is backed up, for example, it’s going to send me down the Arborway to get to Milton.
Waze’s users can also use the app and their desktops to further improve the company’s maps by telling about traffic jams, accidents, road closures, and inaccuracies. So the company’s maps get better over time. I’m sure its Boston-area maps aren’t yet perfect, but so far it hasn’t told me to go the wrong way down a street.
London cabbies and other experienced pros still have an advantage over naive drivers in that they know what turns are coming up, and how the roads are laid out around them. I still occasionally miss turns even with Waze because I’m not exactly sure what to be looking for. Aside from that, though, I think once enough Londoners start using the app the cumulative, current crowd knowledge embedded in Waze will give the system better knowledge than the Knowledge. I bet a video will soon be posted of a Wazer beating a London cabbie in a fair test. Any takers?
And if you don’t have Waze yet, you should get it. It’s free, and your use of it will make me a better driver. So do us both a favor and download it immediately, OK?