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

151–160 of 214 posts

Re: Is Every Speed Limit Too Low?

#151

Post by ackfoo »

The problem with speed limits is that people think they are a license to go that speed, or a little faster, regardless of the conditions. Americans are nearly universally useless at slowing down for things like ice, heavy rain and fog. They ignore things like stopping distance and diminished reaction time in poor visibility.

I agree that there is room for debate on speed limits under ideal conditions on well-maintained roads with bridges that have not been left to rot for decades.

Anyone who has driven internationally will recognize that Americans turn into homicidal/suicidal maniacs when conditions deteriorate--all because they don't understand that the speed limit only applies in ideal conditions.

Driving on U.S. roads in bad weather is a horror show.

Re: Is Every Speed Limit Too Low?

#152

Post by Ygg2 »

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…

> Without exception, a vehicle that moved (much) faster than other traffic around it,

Emphasis mine. Your slower moving vehicle could relate to vehicles moving slower than other cars. Which is what gp claimed.

Re: Is Every Speed Limit Too Low?

#153

Post by rokhayakebe »

ackfoo wrote: post #151

The problem with speed limits is that people think they are a license to go that speed, or a little faster, regardless of the conditions. Americans are nearly universally useless at slowing down for things like ice, heavy rain and fog. They ignore things like stopping distance and diminished reaction time in poor visibility. I agree that there is room for debate on speed limits under ideal conditions on well-maintain…

The problem with speed limits is that people think they are a license to go that speed, or a little faster, regardless of the conditions

I never thought about it that way, and I agree. Speed limit should DEFINITELY be dynamic depending on weather conditions, location, time, traffic etc...

Re: Is Every Speed Limit Too Low?

#154

Post by rokhayakebe »

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…

This is the reason I do not speed. I figured I barely ever drive more than 10-15 miles one way, hence going from 60 to 80 miles per hour is only going to save me a very few minutes and increase my chance at 1) getting a ticket, and 2) wasting 30 minutes when a cop pulls me over.

Re: Is Every Speed Limit Too Low?

#155

Post by Scoundreller »

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…

You still haven't shown that the increased risk of danger outweighs the aggregate time savings. It's a big consideration when looking at things like, the value of screening for unlikely outcomes.

3.5 minutes/trip saved * 2 trips/day * 200 working days per year (probably more) = 1400 minutes saved per year per person.

working-age population of US (2012) = 243 million. Employment-to-population_ratio = 67%, so 162 million.

Let's say that half drive, or 80 million. So, 80m * 1400 minutes = 112 billion minutes a year saved by speeding or 1.9 billion hours. At a wage of $10 per hour, that's $19 billion, which is a bit ahead of the $15b loss of value per your number, but I'm sure our confidence intervals overlap.

112 billion minutes = 213000 person-years of being stuck inside a car saved by speeding. With a US average lifespan of 79, that's 2700 total additional lifespans spent in a car by losing those 3.5 minutes.

Re: Is Every Speed Limit Too Low?

#156

Post by Scoundreller »

TeMPOraL wrote: post #85
dragonwriter wrote: post #75

Earlier quoted context omitted.

> 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,…

That's why I'm for average speed traffic cams and ruthless, fully automatic ticketing of speeders. When the probabilty of getting caught and punished reaches almost certainity, people start to "factor it in regular behavior calculations". But this is going to be a hard sell for both drivers (who feel entitled to their high speed) and law enforcement (which treats ticketing as a revenue source; widespread deployment o…

It would be an easy sell if drivers (such as myself) didn't feel convinced that highway speed limits are arbitrary. 100km/h is a very unlikely number for an engineer to calculate as an upper boundary for a road.

It wouldn't be a tough sell to lower speed limits on some portions, and raise it on others, even on a time-neutral but safety-positive basis, but yet, the powers that be stick to their arbitrary number.

Re: Is Every Speed Limit Too Low?

#157

Post by Spooky23 »

rtpg wrote: post #148
Spooky23 wrote: post #99

Earlier quoted context omitted.

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.

There's a lot of truth to that. Many places use 7-10 mph over as a threshold. Smaller tickets always get plead down, and cops get measured by collars or tickets.

I don't think skirting the limits has much impact on behavior as the limits go up. In my personal observation, I've observed little if any difference between highway driving on the Deegan Expressway in NYC (50 mph), i95 in South Carolina (70/75) or the mass pike (65). Once you hit 70-80 mph, driving requires more attention.

On the other side, you have absurd local limits as well. The standard for streets in most towns in New York was 35 twenty years ago. Now it's 30, with zones as low as 15 or 20 mph near schools. It's a scheme to get bigger tickets and more drug arrests in "school zones". I wish they'd just get to the point and put up a toll barricade.

Re: Is Every Speed Limit Too Low?

#159

Post by spott »

Lagged2Death wrote: post #137
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…

...however the few people that DO [pay attention to speed limits] cause accidents because it makes the differential speed much higher. It's just an abstract that we're discussing here, I know, but the abstract absolutely, categorically does not say that. At all. You're guessing that's what it means .

Sorry, that is from the article (the OP), not the paper that was linked to. The article states that the 10% of people who actually pay attention to the speed limit increase the differential between speeds of cars when the speed limit is too slow.

Re: Is Every Speed Limit Too Low?

#160

Post by greggman »

rokhayakebe wrote: post #153
ackfoo wrote: post #151

The problem with speed limits is that people think they are a license to go that speed, or a little faster, regardless of the conditions. Americans are nearly universally useless at slowing down for things like ice, heavy rain and fog. They ignore things like stopping distance and diminished reaction time in poor visibility. I agree that there is room for debate on speed limits under ideal conditions on well-maintain…

The problem with speed limits is that people think they are a license to go that speed, or a little faster, regardless of the conditions I never thought about it that way, and I agree. Speed limit should DEFINITELY be dynamic depending on weather conditions, location, time, traffic etc...

Sounds like an idea for a startup. Electronic Paper Remotely Updating Speed Limit Signs. Get a government contract to replace all the signs and PROFIT :D
Post reply on HN