Goldilocks driver assistance

By Brian Clegg

One of the interesting things about moving from an ancient car to a recent model is the availability of mechanisms to help the driver. At the extreme level, such as claimed by Tesla, this goes all the way to driving for you (occasionally into things you don’t want to drive into). My car doesn’t go that far, but for me provides three levels that give me what feels, for the moment, to provide the Goldilocks ideal of not too intrusive, not too feeble, but just right.

At the highest level, which I use on motorways and fast dual carriageways, it keeps me at my desired speed, slowing down if there’s an obstacle in front, keeps me in lane and (when it’s in the mood) will change lane when I indicate. The fascinating thing about this is that because the steering movements are very gentle it is almost impossible to detect that it is steering unless you take your hands off the wheel (at which point, the car fairly rapidly starts to complain). Steering is such an automatic thing for an experienced driver that you hardly notice that you aren’t doing it when it involves gentle movements.

If you try to use the same feature on a typically twisty British A or B road, it doesn’t work well. The problem is that this requires constantly making small adjustments to the steering to follow the frequently changing road direction. Manually, this is a smooth operation, but the software makes it feel a touch jerky. (I have no idea if fully self-driving cars have the same problem as they rarely seem to be tested on British back roads, but I suspect they will.) More importantly, it can’t avoid potholes! What is useful, though, if there are vehicles in front going slower than you want to on such roads (as there often are), is to engage the second level of automation, adaptive cruise control. This doesn’t steer, but matches your speed to the vehicle in front.

For back roads without obstacles, or built-up areas, more often than not full manual control seems to be best. Although the adaptive cruise control will slow for some obstacles like sharp bends and roundabouts, it can’t be relied on to keep you at a safe speed – and, frankly, it’s more fun to go DIY on a truly open road.

I could be wrong, but for me this is just the right level of driver assistance. We’ll see what the next car brings…

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Now Appearing is the blog of science writer Brian Clegg (www.brianclegg.net), author of Inflight Science, Before the Big Bang and The God Effect.