Comment by ashtonkem | Hacker News Reader

Comment by ashtonkem | Hacker News Reader

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I’ve always been extremely dubious about the “self driving to save lives” angle for one very specific reason: we already know how to save lives. Slow. The. Cars. Down. Oslo managed to get their car deaths down to 1 in 2019. 1, in a city of 600,000. Los Angeles killed 240 that year, or 36x more per capita.

And yet, we don’t actually apply any known techniques to reduce fatalities. If we really cared about saving lives, we’d implement these measures today rather than banking on a long term tech solution.

I believe that self driving is about a fantasy world in which we can ignore all the negative consequences of a low density, car centric world. Pedestrian deaths? AI magic will solve it. Long commutes? Just eat breakfast in your car! Emissions? Why well just switch over to EVs! Never mind that half of this tech is either not real, or orders of magnitude less efficient than the transit that Europe has used for almost half a century!

The truth is we can fix all of these things right now, but it would involve sacrifices for those whom the system is already benefitting. So instead we’ve made up a fantasy world where we can have our cake and eat it too.

It's a cost benefit calculation. Sure we can make everyone go 25mph, but how much does that slow down commerce? It's a tradeoff people aren't willing to make. They'd rather sacrifice a few lives than take three hours to get 75 miles.

But the self driving tech allows us to get much safer while still going at normal speeds. Or maybe allows us to be equally safe at higher speeds.

Either way it's a win.

First, we only need to slow down cars to 25mph where pedestrians are present. It’s not like cities with low pedestrian fatalities are stuck in the Middle Ages. Places where pedestrians are separated from cars can and should go faster.

Secondly I find it disturbing that discussions around acceptable traffic fatalities focus on unnamed and unspecified people as the apparently acceptable fatalities in pursuit of shorter commutes. I think this let’s a lot of people push off that moral calculus as something that happens to other, lesser, people. See: the reactions once people realized that Uber’s self driving car had killed a homeless woman. A better question is “what is the acceptable level of risk for you and your family to accept in return for faster commutes?”

Finally, don’t underestimate the feedback effect. High speeds are only economically necessary, if they even are, because we’ve chosen to design cities in a way that assumes high speed car traffic. Continuing to focus on keeping traffic going just puts off very necessary and politically difficult discussions about public transit and housing density. We could setup a society where 25mph in the cities works just fine, but we’ve made the explicit choice not to, and continue to reinforce that.

> we only need to slow down cars to 25mph where pedestrians are present.

I don't have the numbers on hand, but I would wager to guess that a good chunk of road injuries and deaths happen not just between drivers and pedestrians, but between drivers and other drivers.

Also, most areas in the US where pedestrians can be present are already limited to 25mph/35mph.

60% of the 2019 road fatalities in Los Angeles were non-drivers. So drivers represent a good chunk, but not even a majority. Of course this statistic is going to very wildly based on which city we’re talking about.

To be fair to my original point, we can also reduce driver fatalities by slowing down highways and offering non-car transit options. The lowest hanging fruit in this area is probably shifting cargo transit from road to rail as much as possible, which might actually save the public money, since interstate highway companies receive billions of dollars in subsidy via subsidized road maintenance.

Secondarily would be high speed rail between major metropolitan areas, which would potentially save both road miles (and deaths) but drastically shorten the commute for some citizens.

>60% of the 2019 road fatalities in Los Angeles were non-driver

Non-driver != pedestrian. Non-drivers include car passengers.

In this case the statistics specifically refer to pedestrians and cyclists, I just shortened it to “non driver” here, which wasn’t an accurate way to summarize the stats.

It kills me that we give such huge hidden subsidies to the trucking industry. Every time this discussion comes up, at least on Reddit, someone always comes out of the woodwork claiming that truckers pay a bunch of fuel tax and registration fees and that proposals to increase taxes on trucking is going to drive up the costs of all goods. For anyone who isn't already aware, the "billions of dollars in subsidy" is in reference to the substantial amount of damage large trucks do to the roads. My Honda Civic going down the road does basically no damage to it at all and it doesn't appreciably damage the road. A large truck going down the road at 80,000 lbs is going to cause far more damage to the road than the fuel tax and registration fees that they paid. Road wear scales to the fourth power of axle weight, so aside from road age itself the vast majority of wear is solely from trucking.

https://www.denenapoints.com/relationship-vehicle-weight-roa...

> I think this let’s a lot of people push off that moral calculus as something that happens to other, lesser, people

The main person I put at risk when driving fast is me. Others too, sure, but mostly me.

So it's not at all bout killing "other lesser people". People mostly just think some risks are worth the reward.

Where I am, Los Angeles, that is simply not true. 60% of the people killed here by a car in 2019 weren’t in a car. And that’s not even accounting for drivers who were driving reasonably and were killed by someone who was not.

I think it is especially relevant in the time of coronavirus to also consider the idea that maybe you just don't need to go into work all the time (or even at regular times) for a large percentage of workers. Just have less cars on the road by running society a little differently.

Because the costs of those measures are not worth the gain.

If you have a million commuters on the streets, each taking a total of an hour a day for their commute, 20 days per month, increasing the average commute time by just 1% effectively costs >300 lives per year.

The basic rule of any change you want to make to the system is that speeds need to go up, not down. Better AI assist systems help speeds go up, therefore they reduce the cost of commuting in human lives.

A car going at 5mph is still going to kill or main a pedestrian if it hits them.

I agree that speed and general "cars forever!" approach is not great, but there is always room for improvement ... e.g. could tech have saved that 1 person who died in Oslo? Why just stop at "the Oslo model"? Why not do that and autonomous tech? It would be worth it if it saved just a handful of lives a year.

Obviously cars and pedestrians should be separated, but you are dramatically understating the impact speed has on pedestrian survival rates.

At 5mph your chance of surviving a collision is extremely high. Heck, you have a 93% chance of surviving a 20mph crash, depending on your age. Survival rates drop off quickly with speed however, with only 80% surviving at 30mph, and 45mph being a 50/50 chance for most of the population.

The effect is that slowing cars down from 35mph to 20mph in areas where pedestrians are close to cars could potentially double the chance of a pedestrian surviving a crash. And that’s not even accounting for how much less likely a collision is to happen at 20mph than 35mph.

Source: https://www.propublica.org/article/unsafe-at-many-speeds

Edit: of course, we can and should add more tech to make cars safer. That’s why backup cameras and seat belts are mandatory, and that’s a good thing. But as an argument for self driving cars, I think that they really come up short when there are tons of effective strategies available right now that we aren’t applying. And that’s my point.

that makes sense given kinetic energy is mass * velocity^2. That squaring of velocity means every mph as they get higher is even more significant than the ones before.

> A car going at 5mph is still going to kill or main a pedestrian if it hits them.

what?

I think this happens fairly often in Manhattan. There's lots of box trucks simply making turns at 5mph and pedestrians crossing obliviously with headphones on or looking at their phones.

Vehicle weight has a large impact on survivability, but not all the way down at 5mph. Plus, vehicles are easy to avoid at 5mph, the majority of the human population can out walk cars at that speed.

That being said, vehicle size is another uncomfortable subject when it comes to road deaths. If we really cared about not killing people on the road, we’d take a long, hard look at what cars we allow to operate on our roads.

Delivery trucks have the benefit of being obviously necessary; I am glad that trucks exist to deliver my food from the train depot (ideally) to my grocery store. But what’s the argument for Suburbans? SUVs not only drastically increase the risk for pedestrians, but they also make the roads more dangerous for other drivers to. For what? Status? A false perception of safety?

Do you realize how slow 5 mph is? There's no way it could kill anyone, even if they're completely not paying attention.

> I agree that speed and general "cars forever!" approach is not great, but there is always room for improvement ... e.g. could tech have saved that 1 person who died in Oslo? Why just stop at "the Oslo model"? Why not do that and autonomous tech? It would be worth it if it saved just a handful of lives a year.

The problem is twofold:

1. Cruise and co. may very well run out of money before they develop tech reliable enough to save people en masse. One proposal decades ago to solve the cars vs people problem was to physically grade separate them entirely, but as it turns out building multistory streets doesn't scale very well.

2. People and politicians, today, are using self driving cars as the magic bullet to avoid spending money on other solutions and changing bad habits. Why spend money on rail or buses if the second coming of Jesus for cars is around the corner? And to a degree, there is an opportunity cost to spending money on unproven X rather than proven Y.

5MPH is roughly as fast as a brisk walk... it should not kill anyone.

Since I can't edit this:

It is not just the energy involved from 5mph - not every accident is a cut and dry collision. A car doing 0.5mph still going to crush your skull when you go under the wheels.

People are killed frequently in London (and I am sure other places) when they are crushed by slow moving vehicles turning left or right and the driver just did not see the person there and they are either slowly run-over and pinned between the vehicle and something else and crushed.

Yes, people do get crushed under the wheels of slow moving cars. But the statistics are extremely clear about what your relative chances of survival are based on vehicle speed. To a first order approximation your chance of being killed by a 5mph car is 0%.

Should we add tech to prevent these accidents? Of course. But let’s not kid ourselves about the actual numbers of where and why cars kill people.

As a means of comparison; back up cameras are mandatory to prevent children from being backed over at slow speed. This is an obvious improvement, but numerically quite small, with estimates being that it saves about 50-70 lives nationally per year. This is far less than the number of pedestrians and cyclists struck and killed in Los Angeles per year alone.

A car doing 0.5mph will be stopped by the driver unless the driver is unconscious.

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