Just How Good Are Driverless Cars?
News comes from Motor City, Detroit, that GM is to equip its new Cadillacs with a range of autonomous driving functions.
News comes from Motor City, Detroit, that GM is to equip its new Cadillacs with a range of autonomous driving functions. The technology can best be considered as a sort of enhanced cruise control, where the car will adjust to traffic conditions and speeds to maintain a safe and consistent cruising speed. It will also steer the car to keep it in the centre of the lane. This is very far from a fully autonomous car but it is the first time that high speed autonomous driving features have been added to a standard production car. In the past, low speed functions such as parking assist have been offered on some models. Almost everyone who is interested in motoring knows that Google is developing a truly autonomous car but as cars with all, or at least some, of these features prepare to take to our roads, it is a good time to look at just how safe and capable they actually are.
Much is made of the safety record of Google’s driverless car. It has reportedly driven hundreds of thousands of miles on California roads without incident. That sounds impressive and reassuring but the true picture may not be quite as clear cut. In fact, Google’s driverless car has been tested only once on US public roads. The test took place on May 1 2012 in Las Vegas and a press release circulated soon after by Nevada’s Department of Motor Vehicles confirmed that the car had passed the test. Just released documents, however, have revealed some slightly less impressive facts about the car’s performance on this test.
These documents reveal for the first time that Google’s car did not perform flawlessly on the test and human driver intervention was required on at least two different occasions. Google was also allowed to choose the test route used for the car. Clearly, this is not a choice that is given to human drivers who sit the test. The choice of routes was permitted to Google because certain road conditions were known to ‘confuse’ the car. Google was also allowed to insist that the driving test took place on a dry and clear day because inclement weather could also apparently prove too challenging to the car’s controls. Despite the company being allowed to take these precautions, its human driver was forced to twice take control during the test.
The test car was a modified Toyota Prius from 2008, boasting the registration plate, ‘AU 001’. It took the test with Google’s Chris Urmson at the wheel. Urmson has since been promoted to head Google’s entire autonomous car programme. Google also had their senior engineer, Tony Levandowski, in the passenger seat and the two Google employees were joined by a couple of Nevada state examiners in the back seats. A bespoke test was devised for the car, designed to discover whether the vehicle could cope with a variety of different motoring situations in full autonomous mode or whether human intervention would be required.
In the ‘pedestrian traffic’ part of the test, the car performed well and the ‘autonomous’ checkbox was ticked by the examiners. These testers also wrote that the car showed excellent recognition capabilities of close-by pedestrians. The car also passed the ‘traffic light’ section with flying colours, staying completely in autonomous mode. The examiners did note, however, that the car was perhaps a little cautious when approaching the lights. Some aspects of driving were not tested at all. Google declined, for example, to test the car on roundabouts, claiming that the rules were unclear and poorly understood by human drivers in any case. The car did deal with unexpected situations extremely competently, coping well when a pedestrian stepped in front of the car without looking and when a cyclist swerved in front of the vehicle.
Where the car didn’t do so well was in the case of interpreting road construction signs. Coming across a blocked lane, the car apparently became confused and stopped, requiring its human driver to intervene twice to continue with the test route.
Clearly the released documents may refer to an earlier version of Google’s autonomous driving system but it is also clear that the cars should face tests that are just as stringent, or even more so, as the tests that human drivers have to sit.