I recently bought a new car, and one of the many toys it came with was Adaptive Cruise Control (ACC).
Technical bit that you can skip if you know what this is: ACC is like ordinary Cruise Control but with a cunning extra feature; a radar is built into the front grille of the car, enabling it to spot traffic ahead and adjust your car’s speed to match the vehicle in front. This ensures that you keep a safe distance from the traffic around you without the driver having to touch the pedals. It’s a big step along the path to a self-driving car.
In slow traffic it’s amazing. Set a speed and it will happily speed up and slow down all on its own according to the traffic conditions. It will bring the car to a complete standstill if necessary, and all that is needed from the driver is a little nudge on the accelerator to set it off again. Genius, right?
Well, not entirely. When the traffic clears and you reach something resembling normal motorway speeds, you discover its major flaw, and this is the flaw that I think will also sink self-driving cars.
Consider the M25 on a busy Monday morning. Most of the M25 has 4 lanes. Lanes 1 and 2 (the leftmost lanes) are generally fairly civilised, but you’re unlikely to be able to drive any faster than 55mph in these lanes; they’re exclusively populated by HGVs and the Terrified Elderly, who drive cars that look like wardrobes on bicycle wheels and sincerely believe that their internal organs will melt if they drive any faster.
To reach 70mph, you’re probably going to need to pull out into lanes 3 and 4. However, these two lanes are the motorway equivalent of The Hunger Games. It’s everyone for him or herself and, if you show even the slightest sign of weakness, there are armies of people in powerful German saloons and SUVs to carve you up, spit you out, and generally treat you with the contempt you deserve. Every inch of space is fiercely fought for and guarded. Forget the two second rule – if there is only a car length plus the depth of a Rizla cigarette paper between you and the car in front, you can be assured that someone will fill it. And it’s here that the ACC falls down. It’s just too damned polite.
Because the ACC system is programmed for safety, it simply doesn’t understand what’s going on. It dutifully leaves a 2 second gap and when, inevitably, someone fills it, it gently slows the car down to re-establish the gap. This leaves space for another person to fill, and so on until you’re going so slowly that even the Terrified Elderly, manically chomping Werther’s originals as they hunch over the steering wheel with white knuckles and beads of sweat running down their foreheads, are going faster than you. If someone attempts the Rizla trick it’s even worse – the ACC actually screams in fear and demands that the driver do something because it can’t cope. It can’t see the Audis on your left accelerating to undertake you and pull out in front, so it doesn’t know that it also needs to accelerate to cut them off. It isn’t aware of the SUV driver busily trying to climb into your boot with his full beam on because you’re going so slowly, leaving a ridiculously huge gap in front of you and generally getting in his way. So in the end, in order to survive and stop irritating everyone else, you have to turn it off and do the driving yourself.
If a small step towards a self-driving vehicle is this hopeless in the Motorway jungle, what hope for the fully autonomous car? It hasn’t got a chance. All the millions of lines of code, AI and Machine learning will be set towards producing a polite car that obeys the Highway Code to the letter, and is totally unprepared to fight for its place on our congested motorways. It will be forced to skulk along with the lorries and the Terrified Elderly in lanes 1 and 2, or become the puny kid having sand kicked in its face by the bigger children if it dares to venture into the outside lanes, because it doesn’t know how to stand up for itself.