Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Is Every Speed Limit Too Low?

priceonomics.com

Post reply on HN
Print view View original

161–170 of 214 posts

Re: Is Every Speed Limit Too Low?

#161

Post by greggman »

satyrnein wrote: post #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.

Well I don't want to die but I also don't want the ticket. In SF between Candlestick Park and Oakland the speed limit is 50 but most traffic goes 65-70.

I have a friend who got his last point going 65 in that area. He pays $7000 a year in car insurance because of his points.

So, I'd rather they raise the speed limit to 65 (so people got 65-70) rather than keep it at 50 which almost everyone but a few (me) ignore.

Re: Is Every Speed Limit Too Low?

#162

Post by greggman »

moneybags4 wrote: post #103

The lower the speed limit, the easier it is to generate traffic ticket revenue. It's a money game. In California, they tell you that whatever the judge tells you your traffic ticket fine is, say $100, your total is 6 times that when administrative fees are added in.

They're more if you add in how much your insurance premiums go up. I believe it's $300 per year per point so $900 for 1 point since they last 3 year. (at least it was $300 a year for me for getting 1 point).

Re: Is Every Speed Limit Too Low?

#163

Post by Dylan16807 »

rtpg wrote: post #147
mrgriscom wrote: post #107

Earlier quoted context omitted.

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…

>At least I'll get to sleep in for 3.5 more minutes.

Come on, that's not a fair argument. The effects are obviously much bigger than one guy saving 3.5 minutes.

To get closer to the meat: If your calculation always outputs numbers that make slower traffic look better, no matter what the starting speed is, then your methodology is wrong. Your method here would make 15mph look better than speeds 20mph or faster, despite a 15mph speed limit being a blatantly terrible idea.

(Also doesn't your assumption of an average speed of 60 bias your argument heavily against high speed limits? I would expect saving 4 minutes on a 30mph route to be much safer than saving 4 minutes off a 60mph route. Is my expectation wrong here?)

Re: Is Every Speed Limit Too Low?

#164

Post by jdbernard »

wiredfool wrote: post #126
autokad wrote: post #80

Earlier quoted context omitted.

i didnt keep riding bicycle faster and faster and faster. i got to a point where i was comfortable at that speed...

Alternate explanation: You got a point where it's physically very hard to go faster. Most people who ride motorcycles or mopeds do it faster than they would on a bicycle.

And yet, as someone who travels almost exclusively by motorcycle, there is a limit to how fast I am willing to go which varies depending on the road I am on. My bike will easily go much faster, and I feel like I could safely command the bike even going fair bit faster, but I am not comfortable going faster on a regular basis.

Re: Is Every Speed Limit Too Low?

#165

Post by Dylan16807 »

dfxm12 wrote: post #72
mwfunk wrote: post #45

Earlier quoted context omitted.

I'm also in the "drive a little under 10 over" camp, and I totally accept that once every 10 years (or whenever), I'm going to be in the wrong place at the wrong time and get a ticket for it. I'm OK with that. It's not fair, but it's well below the bar of meaningful injustice for me to really care about it all that much.

What's not fair about getting a speeding ticket when you are driving over the speed limit?

A largely-randomized system where most participants aren't punished but some are singled out for large fines is pretty unfair.

Performing a bad action does not cause someone to forfeit all arguments as to fairness.

Re: Is Every Speed Limit Too Low?

#166

Post by throwaway5752 »

mrgriscom wrote: post #107
peatmoss wrote: post #15

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…

How much time would we all lose because of the small increased risk of increased traffic accidents and the road closures to clear them? It almost feels like an area of knowledge that I'm clueless about, but someone has spent a lot of time and effort studying.

Re: Is Every Speed Limit Too Low?

#167

Post by eru »

akgerber wrote: post #96

There is very little in this article about the interests of anyone not driving— crash severity is due to speed deltas, and pedestrians and cyclists are almost always moving much slower than automobiles. And a self-interested driver won't slow down to keep pedestrians safe, since pretty all of the consequences of a auto-pedestrian crash fall on the pedestrian.

That's why we need laws to establish strict liability.

Re: Is Every Speed Limit Too Low?

#168

Post by nyc640 »

peatmoss wrote: post #136
spott wrote: post #117

Earlier quoted context omitted.

Respectfully, you didn't read the rest of the abstract to the article you cite, and the next few sentences support what the article says: >Other studies looked at speed dispersion and found evidence that this is also an important factor in determining crash rate. Larger differences in speed between vehicles are related to a higher crash rate. Without exception, a vehicle that moved (much) faster than other traffic ar…

Respectfully, I did, and you're failing to acknowledge what I wrote in my initial posting. > it is saying that speed differential is more dangerous than speed. No it's not, the article is saying that a delta in speed is a factor in crash frequency. (And no, I didn't copy paste the whole abstract, because I was posting the part of the abstract germane to the quote I cited from the original article.) > This is a horrib…

The article isn't claiming that faster speed == safer. It clearly states that raising the speed limit has little effect on the speed that most people travel. The only group of people whose driving speed it significantly affects is the 10% of people who follow the speed limit exactly (who are usually the slowest drivers). Therefore, by raising the speed limit, a large majority of drivers will drive at the same speed (no faster), but the slowest drivers will speed up and the speed differential drops, making the roads safer, as your linked article agrees with.

There was little evidence presented that justified the assumption that most people won't drive any faster with a raised speed limit, but if we take that as true, then its conclusion is consistent with the research you linked. It is NOT making the claim that driving faster is safer. In fact, it again clearly states that in an ideal world, everybody would just travel at slower and safer speeds, but that we can't effectively enforce such a low speed limit.

Re: Is Every Speed Limit Too Low?

#169

Post by rtpg »

Dylan16807 wrote: post #163
rtpg wrote: post #147

Earlier quoted context omitted.

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…

>At least I'll get to sleep in for 3.5 more minutes. Come on, that's not a fair argument. The effects are obviously much bigger than one guy saving 3.5 minutes. To get closer to the meat: If your calculation always outputs numbers that make slower traffic look better, no matter what the starting speed is, then your methodology is wrong. Your method here would make 15mph look better than speeds 20mph or faster, despit…

actually my argument is based more around 60 mph average speed because that's more or less the average speed on highways and people spend a decent amount of time driving on highways and the like. Also, the increased fatality rates were concerning a rise from 60 to 70mph.

Obviously if we're going from 15 to 20 the numbers change. But at the same time if people were on average driving around at 15mph on average car accidents wouldn't be such a big issue, instead of the leading cause of death among teenagers.

actually with lower speed limits you would gain more time by going 10mph faster. For example, if people were driving at 10mph on average, going 20mph would half their transit time. The point is that the speeding people commit usually doesn't earn them much more time, but disproportionately endanger themselves and those around them at higher speeds.

Re: Is Every Speed Limit Too Low?

#170

Post by gnur »

cfstras wrote: post #66
cylinder wrote: post #54

Earlier quoted context omitted.

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…

Exactly -- sure, you can still hide behind a truck and go 100 km/h all the time -- but most cars efficiency sweet spot is around 130 km/h, and driving at that speed leads to more dynamic, occasionally passing trucks, etc.

What is an "efficency sweet spot"?

When I consistently drive at the speed limit (in the Netherlands, 120km/h) I have to fill up every 4 working days. When I consistently drive 100 km/h I only have to fill up every 5 working days. Takes 20% longer but the tank also lasts 20% longer.

Post reply on HN