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Is Every Speed Limit Too Low?

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Re: Is Every Speed Limit Too Low?

#71

Post by ameister14 »

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 think it's pretty interesting that you advocate for narrower roads and short setbacks because you belive that on roads like this people are less likely to speed.

I don't know if people are less likely to speed on those roads; I think it is unlikely because growing up in a small town, people speed on backwoods roads all the time. Still, I'm not sure that this is the case.

What I do know is that roads like that are less safe, particularly if you DO speed.

So, unless you can show me that making a road less safe for speeding reduces the rate at which people drive, I'm going to keep thinking that that argument is like saying you can't give out condoms to kids because it makes them more likely to have sex.

Re: Is Every Speed Limit Too Low?

#72

Post by dfxm12 »

mwfunk wrote: post #45
incision wrote: post #24

Earlier quoted context omitted.

>'That's (supposedly) because a ticket for anything less than 10mph is simply not worth it for the cops.' Depends on your cops. I've witnessed tickets for 5 over (40 in a 45), 4 over (49 in a 45) and a stop, thankfully without a ticket for 1 over (31 in 30). I'm given to thinking of it as a lottery. Someone is getting pulled over, today me, tomorrow someone else. I'm just glad I haven't had a case of 'marijuana smell…

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?

Re: Is Every Speed Limit Too Low?

#73

Post by autokad »

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…

the article repeatedly mentioned: raising speed limits does not raise driving speeds on roads. humans are kind of strange in the fact that they drive at a speed they are comfortable with.

also, while that (faster = crash more) may be true, its not the only thing going on. it may be the case (and one argued in the article) that driving speed differences results in more crashes.

Re: Is Every Speed Limit Too Low?

#74

Post by gaius »

reitanqild wrote: post #67
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…

Mentioned this in another thread and I'm still looking for researh around this topic: A Dutch engineer once told me (back before 2004 I guess ) that they once raised the speed limit on the roads in Netherlands and found that counterintuitively, - average speed decreased. His explanation IIRC was that 1. once people break the rules it doesn't matter how much and 2. when speed limits felt more correct more people respe…

Let's not forget that the speed limit was never about safety. It was about saving fuel in an oil crisis.

Re: Is Every Speed Limit Too Low?

#75

Post by dragonwriter »

peatmoss wrote: post #64
tux1968 wrote: post #36

Earlier quoted context omitted.

Heh, fair enough to be sure. However the video and the associated article that I linked do in fact reference multiple official studies. Examples: - http://www.fhwa.dot.gov/publications/research/safety/97084/9... - http://www.th.gov.bc.ca/publications/eng_publications/speed_...

Generally, worth taking government reports with a grain of salt. I've participated in a few, and the standards are often much lower than peer-reviewed articles. That said, on a quick skim, I don't see anything that strikes me as being obviously wrong / overturned (FHWA was 1997). But, I also don't see either source providing justification for driving faster. Both reports seem to accept this (in fact, this is about as…

> If people respond to a combination of law and roadway design (perhaps leaning more heavily on the latter), and we want behavior in line with law, what should we do? Ease the law or change the roadway design?

Or change the context in some third way (e.g., enforcement)? The thing with roadway design is that the roadway designs which enourage higher speed are generally the same ones that are safer at any given speed, so changing the design to reduce the incentive for high speed may not improve safety as much as the reduced "natural speed" would seem to suggest -- and may retain the high delta beteween fast drivers and slow drivers that you note is a major factor in accidents, just reducing the median.

But what if through technology we could get enforcement of existing limits to a place where the probability of penalty for violations was higher (even if the penalty range had a lower bottom end)? One problem with law as an factor in behavior right now is that the probability of any given violation (or even a pattern of consistent violations) being punished is so low that the law serves more as a very weak social signal and the source of an inverted lottery of punishment than as a rational utility factor in regular behavior calculations.

With more consistent enforcement, we may be able to reduce the delta between high and low speed drivers (as the high speed end is usually significantly above the legal limit) without changing the law (at least, the speed limits in the law) or the road design significantly.

Re: Is Every Speed Limit Too Low?

#76

Post by Theodores »

clairity wrote: post #57
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…

speed definitely increases the severity of crashes, but i'm not convinced that it increases frequency. even so, the #1 factor leading to increased frequency of crashes is distracted driving (sorry, don't have time to look up relevant links). if it exists, the correlation of accidents with speed is likely much weaker than with distractedness. if we really wanted to reduce motoring accidents, rather than regulating spe…

Maybe we should go back to Cadillac Eldorado 'bullet' style steering wheels (and no seatbelts) which really were as much use as a spike in the middle of a steering wheel.

Re: Is Every Speed Limit Too Low?

#77

Post by dfxm12 »

saticmotion wrote: post #65

I didn't get this from the article, but are there no automated cameras in the USA? In Belgium there are tons (I pass 5 on the 10 minute drive to my girlfriend), but they're a joke. If people know the road they're taking, they drive however fast they like, until they get near a camera. They slow down until they're out of reach and then speed up again. Also only about 1/3 actually have a camera in them, but they get ro…

In the US, automated cameras are generally limited to capturing people driving through red lights, if they are used at all.

Re: Is Every Speed Limit Too Low?

#78

Post by tmp1234519029 »

cheald wrote: post #47
peatmoss wrote: post #43

Earlier quoted context omitted.

I've always loved this example. I lived in MT pre, during, and after this experiment. We went from: - 65 Mph - "Reasonable and prudent" daytime speed - 75 Mph daytime speed During the reasonable and prudent period, I think many people still had an internal model of 65 Mph. Certainly many people did drive faster. In my younger days, friends and I would find straight, empty sections of highway to flirt with death. But.…

Very interesting. How well do you think that 65 MPH internalized limit (during R&P) mapped to the 85/15% split as described in the original article? Do you have any other insights into other factors that might have contributed to the change in fatalities, or do you think it was just as simple as "people are driving 10 MPH faster on average", with correlated increases in fatality rates?

My guess:

- R&P: people look at the road

- 75 : people look for cops (if they're above speed limit)

Re: Is Every Speed Limit Too Low?

#79

Post by bryanlarsen »

autokad wrote: post #73
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…

the article repeatedly mentioned: raising speed limits does not raise driving speeds on roads. humans are kind of strange in the fact that they drive at a speed they are comfortable with. also, while that (faster = crash more) may be true, its not the only thing going on. it may be the case (and one argued in the article) that driving speed differences results in more crashes.

"raising speed limits does not raise driving speeds on roads"

I suspect that's a temporary effect. The speed people are comfortable at is mostly a learned phenomenon. The more they drive fast safely, the more comfortable they feel.

Remember when you first started riding your bicycle? 10 mph was super fast and was super scary. And it is; that's faster than the speeds that the human body was evolved to support.

Re: Is Every Speed Limit Too Low?

#80

Post by autokad »

bryanlarsen wrote: post #79
autokad wrote: post #73

Earlier quoted context omitted.

the article repeatedly mentioned: raising speed limits does not raise driving speeds on roads. humans are kind of strange in the fact that they drive at a speed they are comfortable with. also, while that (faster = crash more) may be true, its not the only thing going on. it may be the case (and one argued in the article) that driving speed differences results in more crashes.

"raising speed limits does not raise driving speeds on roads" I suspect that's a temporary effect. The speed people are comfortable at is mostly a learned phenomenon. The more they drive fast safely, the more comfortable they feel. Remember when you first started riding your bicycle? 10 mph was super fast and was super scary. And it is; that's faster than the speeds that the human body was evolved to support.

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