And it seemed like everything was going so well for Google’s amazing new driverless cars. The first set of prototypes has been tested; they’ve driven over 700,000 miles of US roads; they’ve even created a second generation two-seater car with what looks like a friendly face on the front:

Aww, look at its smiley face.

So you could be forgiven for thinking that Google were on the home straight, and we’d all be chauffeured around in autonomous vehicles before the year was out.

But, it turns out, not so much. The most recent issue of MIT Technology Review has revealed a list of the things the cars can’t yet do, as confirmed by Chris Urmson, director of the Google car team. These range from the mildly problematic  – for example, the cars can’t detect the nature of an obstacle, so would swerve around balls of paper as though they were rocks…

…to the downright concerning. Such as not having been tested in adverse weather conditions such as snow or rain. Or being able to detect open manhole covers or potholes.

Perhaps the most worrying issue, however, is the fact that they still can’t operate on most roads. The cars rely on painstakingly detailed 3D maps, which require multiple visits to streets and analysis by both humans and computers: simply downloading Google Maps won’t cut it. And, since the cars can’t respond to unexpected visual signals, like temporary route changes or new sets of traffic lights, these maps must also be updated constantly. That’s a lot of effort, and so comes at a cost.

Urmson assured the publication, however, that engineers are hard at work on all these issues, and he still hopes the cars will be on roads within the next five years, by the time his 11-year-old son turns 16: “It’s my personal deadline.”

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