Until cars can read road signs, we can’t expect them to read dangerous situationsFri, 26/05/2017
Self-driving cars have been a hot topic in the news, but perhaps there’s something important that’s been overlooked? Whilst a self-driving car may be able to monitor the car in front and perhaps even read a sat nav, are they able to read road signs?
Ed Wiseman, Yahoo! News, reports:
I can't think of anywhere on our planet where the speed limit is 145mph. There are autobahns in Germany where that sort of speed is permitted, and maybe a smattering of roads around the world where you might get away with it, but nowhere – nowhere – has a speed limit of 145mph.
You can imagine my surprise, then, when our Peugeot 3008 long-termer displayed that same figure on its dashboard, in black numbers on a white background with a red ring around it. On paper it's a clever feature, one that provides a constant visual reminder of the prevailing speed limit during that confusing half-mile between signs. But in practice, the car's best efforts at reading comprehension are often dangerously inaccurate.
Since the change in speeding penalties a few weeks ago, I've been paying particular attention to the speed limits suggested by traffic sign recognition systems. Previously I'd dismissed this feature as just another gimmick that everybody knows is a waste of time, like voice recognition and resistive touchscreens, but that's a flippant attitude towards something as important as my car's velocity.
And with the looming availability of self-driving cars, the feasibility of which will depend wholly on their ability to accurately interpret their surroundings, it's about time this decade-old technology started to deliver on its promises.
So in the interests of fairness, it's worth pointing out that the Peugeot 3008 is far from the worst offender. In terms of traffic sign recognition inaccuracy, the £100,000 Range Rover SDV8 Autobiography was surprisingly haphazard. In particular, it seemed to misinterpret a '20' as a '70', repeatedly assuring me that the speed limit was 70mph in parts of London that had narrow, busy streets. It suggested 70mph again on the Greenwich Peninsular, seemingly at random, before settling on 30mph (which was also wrong).
The incorrect figures aren't always dangerously high. Sometimes they're overly cautious, like the apparent 15mph limit (again in the Range Rover) somewhere in rural Surrey. I'm confident that the speed limit was 30mph at the time, but it's possible that the system misinterpreted a sign on nearby private land as something that I needed to worry about.
Consistently accurate systems are in the minority. The VW Golf R estate was largely accurate around town (apart from one notable exception that I'll come on to) but failed to notice changes on the dual carriageway. The Jaguar F-Pace and Land Rover Discovery seemed occasionally confused but also had the good grace to admit it, displaying nothing instead of an incorrect number. And don't get me started on the otherwise-excellent Mercedes E-class.
Such an egregious discrepancies are easy to spot. The Peugeot won't do 145mph, and I was in France at the time (with the dash still set to mph) so was already paying more attention than usual to the speedometer. Similarly, I know that there aren't any roads in Mile End with a speed limit of 70mph, no matter what the Range Rover reckons. And I'm sure that Surrey doesn't have any 15mph limits, because nowhere has 15mph limits.
It probably isn't those differences that matter the most – they're just entertaining examples. But for every time the car makes one of these funny mistakes, it might make ten smaller, more serious ones. 40mph in a 30mph zone is much more dangerous than 80mph on a dual carriageway. And all of these humorous quirks and idiosyncracies are turned into dangerous malfunctions when combined with, for example, adaptive cruise control, which will actually change the speed of your vehicle based on this flawed information.
There are many reasons why self-driving cars reading road signs is a vital aspect of safe driving. For example, what if there has been an emergency lane closure? What is there’s an emergency diversion? Ignoring road signs puts both the driver and passengers, and other road users, at risk. This is why accurately reading road signs is an integral part of self-driving cars.