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The Humans Crashing Into Driverless Cars are Exposing a Key Flaw (bloomberg.com)
schwit1 sends in a story from Bloomberg pointing out that the rigid adherence to traffic laws and overcautious programming have caused self-driving cars to rack up a crash rate twice that of an average human driver. "This may sound like the right way to program a robot to drive a car, but good luck trying to merge onto a chaotic, jam-packed highway with traffic flying along well above the speed limit. It tends not to work out well. As the accidents have piled up — all minor scrape-ups for now — the arguments among programmers at places like Google and Carnegie Mellon University are heating up: Should they teach the cars how to commit infractions from time to time to stay out of trouble?" While the autonomous vehicles aren't at fault in these crashes, their relative unpredictability on the road are nonetheless leading to more accidents than expected.
If you're not overtaking, you have no business being in that lane. That's what the outer lanes are *for*. It's people who don't understand that simple rule that cause accidents. Undertaking is illegal e.g. in the UK for a reason.
Oh there is a reason, it just has nothing to do with safety.
Or there is a reason, it has to do with safety, or with optimising throughput, or some other valid concern, but that reason is not obvious to every dummy driver on the street.
The throughput argument bears repeating. Many drivers don't understand this, but sometimes you can get more people through a bottleneck (AND have fewer accidents) if everyone drives more slower at a constant speed than if everyone is trying to drive faster at the same traffic density. This is particularly true when you have a high variability of vehicle speeds, like in a mountainous area where trucks are forced to go slower or in an urban area where frequent incoming and outgoing traffic at exits often travel at different speeds from the rest of the highway.
For example, if you're driving on a highway through an urban area and they lower the rush hour speed limit to 45 mph (some areas now are adopting such dynamic speed limit signs), the idea is that if cars actually go 40-45 mph, the road will actually be able to handle the amount of traffic while also allowing all the people merging on, getting off at exits, changing lanes, etc. at a safe speed.
If, instead, everyone tries to drive 65-70 in the same area, what can happen is that the merging or changing lanes will eventually cause someone to cut someone else off, which causes sudden braking, which then causes some tailgaters behind them to brake suddenly, others follow and overcompensate because they were going too fast and suddenly see much slower cars, and within a few minutes you have a "traffic wave" of stop-and-go traffic backed up for a few miles which might take a half-hour to resolve, where throughput is dramatically reduced. (How many times have you gotten to the end after sitting through 10 minutes of such stop-and-go traffic waves, and there's nothing there -- no accident, no merge, etc.? This is often the kind of thing that happened.)
At a slower speed, the slower car may not have been forced to "cut someone off" in the first place, or if he does, the impact of a bit of braking may not cause such massive changes and overcompensation. Traffic thus recovers faster and throughput is maximized.