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Is Every Speed Limit Too Low?

priceonomics.com

141–150 of 214 posts

Re: Is Every Speed Limit Too Low?

#141

This article ignores a lot of peer-reviewed literature from planning, public health / injury prevention, and civil engineering in favor of some folksy wisdom of a lieutenant cop. A good starting mental model is that vehicle speeds increase both the frequency and severity of crashes. The article weakly, and quietly made an argument that I do agree with. Namely, roadway design needs to accompany speed limits to ensure…

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Re: Is Every Speed Limit Too Low?

#142
post #92

I think that the road design is a key factor in how fast people drive, not limits. Wide lanes, one-way streets, and cleaned-up sides without obstacles encourage driving faster while narrower passes and trees/bushes on the side make you naturally slow down. On a road or street well designed you would drive at the limit even if you didn't know what the limit is because the limit is set to the "natural" speed of the roa…

A similar effect can be noticed on sections of roads with dedicated overtaking lanes. Cars that are travelling below the speed limit for long stretches of road (and can't be overtaken due to the road), tend to speed up to the actual speed limit when an overtaking lane comes along - likely due to the more open road, they feel safer driving faster, etc.

This makes it more difficult for all the (often frustrated) drivers behind to pass the slow car when the time comes, often meaning they put on the afterburners and exceed the speed limit to overtake - which could lead to more accidents, especially if they are trying to squeeze past at the end of the overtaking section, if it is quite short, or there are many cars stuck behind as 'prisoners'.

Re: Is Every Speed Limit Too Low?

#143

Earlier quoted context omitted.

The article repeatedly mentions that there is very little correlation between posted speed limits and traffic speed. He goes to great pains to explain that traffic speed seems to be independent of speed limits. The paper you quote states that there is a correlation between accident frequency/severity and actual speed not speed limits. The argument in your comment is based on precisely the fallacy that the article say…

And yet occasionally lets slip quotes like the one I posted earlier, in which the officer sites anecdata that speed isn't the problem. The article I posted was specifically countering that notion. The broader issue I have with this article is its prescription for bringing speeds and speed limits closer together--namely increasing the speed limits. I think using roadway engineering to decrease the speeds is actually a…

If you are talking about an urban boulevard, then I agree. Engineer the street to lower speeds, and increase safety because there are pragmatic options (roundabouts, speed bumps, more signals and stop signs. But if you are talking about intercity highways, something like Los Angeles to Phoenix to Denver to Des Moines, then just increase the speed limit.

Re: Is Every Speed Limit Too Low?

#144
The assumption is that there's no enforcement mechanism, so you might as well give better guidance to the few people who comply voluntarily.

Perhaps the police will just go the other way and have a fleet of drones enforce compliance.

Re: Is Every Speed Limit Too Low?

#145

This article ignores a lot of peer-reviewed literature from planning, public health / injury prevention, and civil engineering in favor of some folksy wisdom of a lieutenant cop. A good starting mental model is that vehicle speeds increase both the frequency and severity of crashes. The article weakly, and quietly made an argument that I do agree with. Namely, roadway design needs to accompany speed limits to ensure…

I'm annoyed that the taboo thing to say in this discussion is whether increased traffic fatalities is always an inherently bad thing. When you're talking about societal-scale policy, it's impossible to make anything 100% safe; rather, it's about acceptable trade-off in risk. We could make a universal speed limit of 10mph and traffic deaths would probably vanish, but we don't because the impact on transport is too gre…

I hate slippery-slope arguments, but I feel that if you are going to advocate the scenario you seem to have advocated, then you can take it a lot further. For example I feel that anyone whose car stalls while crossing the San Francisco-Oakland Bay Bridge should be banned from driving for life. Because every time someone stalls on the bridge at rush hour there's a traffic jam clear back to Reno.

Re: Is Every Speed Limit Too Low?

#146
post #44

Disclaimer: I am from Germany. The speeding system we have here seems to make a lot more sense to me: On most highways, there is no speed limit. The only (theoretical) limit is the motor limitation of 155 mph (250 km/h), which can be taken out, but will almost always lead to losing any kind of motor warranty. In practice, there are limiting signs to 75 mph (120 km/h) for passages where the road is not good enough or…

Yes, the main point is that I pay more attention when driving faster on a freeway. One need only take a road trip in Australia to see how ridiculous low speed limits on open roads are. 110 kmh limit with, yes, very strong enforcement in place, in a completely rural area with few cars around, no people, no pedestrians, on a long drive (it's ten hours from Melbourne to Sydney with basically nothing in between). Result…

Australian traffic camera tolerances are also set ridiculously low, and there are far too many variations in limits.

I fully support 50kmh urban street limits, but the open road sections should have a day/night limit, where the day limit is 130, like most of Europe and some parts of the US. There should also be limits to how often a speed limit can change in a single stretch of road, and highway speed zone changes should have a minimum of three signs at even spacing to indicate the change approaching, at the spot and one more reminder.

There should also be a ban on concealed traffic cameras - getting a fine long after the event has very little effect on the behaviour, apart from generating feelings of injustice.

Re: Is Every Speed Limit Too Low?

#147

This article ignores a lot of peer-reviewed literature from planning, public health / injury prevention, and civil engineering in favor of some folksy wisdom of a lieutenant cop. A good starting mental model is that vehicle speeds increase both the frequency and severity of crashes. The article weakly, and quietly made an argument that I do agree with. Namely, roadway design needs to accompany speed limits to ensure…

I'm annoyed that the taboo thing to say in this discussion is whether increased traffic fatalities is always an inherently bad thing. When you're talking about societal-scale policy, it's impossible to make anything 100% safe; rather, it's about acceptable trade-off in risk. We could make a universal speed limit of 10mph and traffic deaths would probably vanish, but we don't because the impact on transport is too gre…

The tradeoff for speeding is stupidly small.

Average US worker spends 25 minutes on a one-way trip to work. Lets assume an average speed of 60mph (hint: it's slower). If you went at 70 instead of 60, then you'll save a whole 3.5 minutes.

Here(http://webcache.googleusercontent.com/search?q=cache:jWbI1mK...) is a link to a NHTSA presentation on speed limit changes and its effects on crashes. Notably, when states were given control of speed limits, we saw raises from 60-65 to 70-75 mph in some situations, and a 35% increase in fatalities.

if we do the whole "life is worth $3M dollars" argument, divide by two because I'm trying to make this favorable to you (even though car fatalities disproportionately affect young people), letting people go 70 instead of 60 could still end up causing almost 10k more deaths per year, so there's $15B in lost value per year. At least I'll get to sleep in for 3.5 more minutes.

Re: Is Every Speed Limit Too Low?

#148

This article ignores a lot of peer-reviewed literature from planning, public health / injury prevention, and civil engineering in favor of some folksy wisdom of a lieutenant cop. A good starting mental model is that vehicle speeds increase both the frequency and severity of crashes. The article weakly, and quietly made an argument that I do agree with. Namely, roadway design needs to accompany speed limits to ensure…

End of the day, you shouldn't have laws that 80% of the population breaks during the ordinary course if business. I've found myself in vehicles towing trailers where 65 mph was about as fast as I could go. I continuously had cars passing me. If everyone is a criminal, something is wrong with the law.

Well, there seems to be this myth that its OK to speed 5 miles above the posted speed limit, so the speed limit is still useful. It'll just be limiting the speed to 60 instead of 55.

As to whether things are enforced that way, that's a different story.

Re: Is Every Speed Limit Too Low?

#149
Since this is HN, what about technological solutions? Better speeding cameras could enforce speed limits universally. Self driving cars would obey speed limits automatically, however they could safely drive at much faster speeds than humans (albeit with significantly reduced fuel efficiency, which I think will be an issue.)

Re: Is Every Speed Limit Too Low?

#150

This article ignores a lot of peer-reviewed literature from planning, public health / injury prevention, and civil engineering in favor of some folksy wisdom of a lieutenant cop. A good starting mental model is that vehicle speeds increase both the frequency and severity of crashes. The article weakly, and quietly made an argument that I do agree with. Namely, roadway design needs to accompany speed limits to ensure…

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