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Insurance Institute for Highway Safety

So how safe are those driverless cars?

Safer than human-driven cars, but maybe not by as much as you might think.

A new study says that while autonomous vehicle technology has great promise to reduce crashes, it may not be able to prevent all mishaps caused by human error.

Auto safety experts say humans cause about 94% of U.S. crashes, but the Insurance Institute for Highway Safety study says computer-controlled robocars will only stop about one-third of them.

The group says that while autonomous vehicles eventually will identify hazards and react faster than humans, and they won’t become distracted or drive drunk, stopping the rest of the crashes will be a lot harder.

“We’re still going to see some issues even if autonomous vehicles might react more quickly than humans do. They’re not going to always be able to react instantaneously,” said Jessica Cicchino, and institute vice president of research and co-author of the study.

The IIHS studied over 5,000 crashes with detailed causes that were collected by the National Highway Traffic Safety Administration, separating out those caused by “sensing and perceiving” errors such as driver distraction, impaired visibility or failing to spot hazards until it was too late. Researchers also separated crashes caused by human “incapacitation” including drivers impaired by alcohol or drugs, those who fell asleep or drivers with medical problems. Self-driving vehicles can prevent those, the study found.

However, the robocars may not be able to prevent the rest, including prediction errors such as misjudging how fast another vehicle is traveling, planning errors including driving too fast for road conditions and execution errors including incorrect evasive maneuvers or other mistakes controlling vehicles.

For example, if a cyclist or another vehicle suddenly veers into the path of an autonomous vehicle, it may not be able to stop fast enough or steer away in time, Cicchino said. “Autonomous vehicles need to not only perceive the world around them perfectly, they need to respond to what’s around them as well,” she said.

Just how many crashes are prevented depends a lot on how autonomous vehicles are programmed, Cicchino said. More crashes would be stopped if the robocars obey all traffic laws including speed limits. But if artificial intelligence allows them to drive and react more like humans, then fewer crashes will be stopped, she said.

I’ve been watching the Amazon series Upload (very funny, check it out), and one plot point in it is the death of two characters in separate autonomous vehicle crashes. Feels a bit more salient after reading this. This is more a model than a study, and it may well be that driverless cars do better, or eventually get to do better, than what this predicts. But one of the selling points of driverless cars is that they will be able to go faster and in denser traffic than human-driven cars can go, which will save time, allow for less road construction, and provide options for mass transit that are currently unthinkable. Those things are a whole lot less feasible if this model is accurate. Sure, a one-third drop in crashes would be excellent, but that’s not transformative. Under those assumptions, we’ll get the driverless cars, but other than not driving the overall experience won’t be much different.

Study says red light cameras save lives

Now they tell us.

In a study released on Tuesday, the Insurance Institute for Highway Safety, found that red-light cameras could save lives.

The findings by the institute, a nonprofit group funded by the insurance industry, found that from 2004-8 the cameras saved 159 lives in 14 of the biggest American cities. Extrapolating from these findings, researchers claimed that had red-light cameras, which capture digital photographs of vehicles that supposedly run a red light, been operating during that same five-year period in all large American cities, 815 lives would have been saved.

Crashes that result from running a light are commonly known as T-bone crashes, in which a vehicle running a light collides with the side of another vehicle — the type of crash in which occupants in the impacted car are particularly vulnerable because there is comparatively little material to absorb the impact.

According to government data, 676 deaths were caused by red-light running in 2009, a decrease from 2001, when 1,009 deaths were reported.

Of 99 American cities with more than 200,000 residents in 2008, the researchers identified 14 that had installed traffic cameras from 2004-8. These cities became the primary study group, requiring two date ranges — one spanning a period during which no cameras were installed (1992-96) and another comprising the years during which they were installed (2004-8) — for researchers to effectively measure the rate of change.

The comparison group, meanwhile, included 48 cities that never installed cameras. For consistency, researchers split these cities’ fatality data into the 1992-96 and 2004-8 date ranges.

In the 14 cities where cameras were installed, the combined per capita rate of fatal red-light crashes fell a combined 35 percent, relative to those cities’ 1992-96 data. The fatality rate also fell in the 48 cities in which no cameras were ever installed, but by 14 percent.

The IIHS news release is here and the study is here. I don’t expect this to change anyone’s mind, and it’s all a moot point as far as Houston is concerned, but there you have it.