5 ms·

The likelihood of death is proportional to speed [1], and the speed is lower in the urban cores. The math is super simple, and let's stop trying to justify bad

by jablan 9y ago

The likelihood of death is proportional to speed [1], and the speed is lower in the urban cores. The math is super simple, and let's stop trying to justify bad urbanistic (essentially, political) decisions blaming it on the bad fate instead. [1] http://www.copenhagenize.com/2012/11/the-85th-percentile-folly.html http://www.copenhagenize.com/2012/11/the-85th-percentile-fol...

eveningcoffee 9y ago
This is simply wrong in the general case. While the speeds might be lower, they are still high enough to kill. In addition the density of the traffic can be so high that just a single wrong step can decide your destiny every minute.
- jablan 9y ago
  Do you have some numbers to support your claims?
  - todd8 9y ago
    Yes, From CDC: > In large central metro areas, those aged 35–44 years (2.08), 45–54 years (2.60), 55–64 years (2.60), 65–74 years (3.36), 75–84 years (5.19), and ≥85 years (5.24) had statistically higher death rates than those in the same age groups at other urbanization levels. [1] [1] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6215a1.htm https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6215a1.htm
    - lsc 9y ago
      most US metros don't have workable public transit; most people drive to get from point a to point b even in our dense metros. Perhaps because even our metros are not dense enough, perhaps for other reasons. I would be open to data that showed there were more traffic deaths in dense areas where most people took public transit, but this isn't it.
    - AstralStorm 9y ago
      Does this hold adjusted for miles driven?
  - eveningcoffee 9y ago
    Well, my claim was mostly that the speed is not the only factor but also the traffic density.
thomastjeffery 9y ago
Speed is the most quantifiable factor in a collision. It is also very controllable. That is why it gets the focus that it does. The trouble is, it's easy to get distracted by speed as a coefficient in collision intensity, and not pay attention to what causes that collision in the first place. People often think that because speed is such an important factor that they shouldn't drive faster to help traffic flow, or even that they should block faster traffic. Those actions are very likely to cause collisions, which is more important than the factor they are trying to minimize. The likelihood of a collision causing death is just as proportional to mass. A semi hauling a trailer cannot stop in a short enough distance to prevent some collisions, and can be deadly even at very low speed. Even so, we realize the impracticality of reducing mass, so we focus on speed instead. The real problem we need to focus on is collision prevention, not collision mitigation. Let's stop ignoring the reality of "bad fate", and do real work to minimize it's occurrence instead.
- sliverstorm 9y ago
  Reducing speeds is a form of collision prevention, is it not? A typical car can just about stop on a dime at 15mph, and a pedestrian has more time to react. There's a whole slew of other pedestrian-friendly street design that we could & should adopt as well, but that doesn't make speed any less of a valid approach.
  - hermitdev 9y ago
    Speed, in of itself, is not dangerous. What is more dangerous on highways is differential speed. i.e. if you're driving 60 mph when the traffic around you is doing 80 mph, you're the problem. Probably exponentially so if you're driving slowly in the "fast" lane. While rarely enforced, most states in the US have laws that require you to pull to the right if you're impeding traffic (usually defined as holding up +2 vehicles behind you) - even if you're doing the speed limit. Yet, these laws are rarely enforced, just like "No Trucks Left 2 Lanes" is never enforced in & around Chicago, despite being posted every mile or so on I 294. I'd wager, also, that speed itself is rarely the direct cause of an accident. High speed, though, will make an accident more severe. My bet is that distracted driving is the #1 cause of accidents. On my daily 2-hour round trip on Chicagoland highways, I usually see 4-6 accidents each involving >2 cars. The shear amount of people I see on their phones is staggering. Hard to tell if it's social media or texting, but you can always tell because their head is staring at their lap, or they're holding their phones at the top of the steering wheel for all to see. I also see people with their phones mounted on their dashes watching movies or TV shows. Playing with your phone while driving is far more dangerous than paying attention & speeding.
mulmen 9y ago
Even if your claim is true it's still not the point of the article.
- labster 9y ago
  The point of the article is wrong, though. Anyone could have done it. All of us drivers could have killed Brian. We just weren't the unlucky ones. But it is not just the author's fault, it is all of our faults. The road system is designed with inherent danger. The street she was driving had a high speed limit with children near the road. If we design better systems, then no one has to live with needless guilt. And, even better, less people die.
dahart 9y ago
Super agreed on the gist - speed limits and policy matter, if we want to reduce fatalities. But, just to clarify and double down on speed reduction -- likelihood of death is proportional to the square of velocity. Every doubling of speed is 4x more damage in a collision!

by jablan 9y ago

eveningcoffee 9y ago

This is simply wrong in the general case. While the speeds might be lower, they are still high enough to kill. In addition the density of the traffic can be so high that just a single wrong step can decide your destiny every minute.

jablan 9y ago
Do you have some numbers to support your claims?
- todd8 9y ago
  Yes, From CDC: > In large central metro areas, those aged 35–44 years (2.08), 45–54 years (2.60), 55–64 years (2.60), 65–74 years (3.36), 75–84 years (5.19), and ≥85 years (5.24) had statistically higher death rates than those in the same age groups at other urbanization levels. [1] [1] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6215a1.htm https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6215a1.htm
  - lsc 9y ago
    most US metros don't have workable public transit; most people drive to get from point a to point b even in our dense metros. Perhaps because even our metros are not dense enough, perhaps for other reasons. I would be open to data that showed there were more traffic deaths in dense areas where most people took public transit, but this isn't it.
  - AstralStorm 9y ago
    Does this hold adjusted for miles driven?
- eveningcoffee 9y ago
  Well, my claim was mostly that the speed is not the only factor but also the traffic density.

thomastjeffery 9y ago

Speed is the most quantifiable factor in a collision. It is also very controllable. That is why it gets the focus that it does. The trouble is, it's easy to get distracted by speed as a coefficient in collision intensity, and not pay attention to what causes that collision in the first place. People often think that because speed is such an important factor that they shouldn't drive faster to help traffic flow, or even that they should block faster traffic. Those actions are very likely to cause collisions, which is more important than the factor they are trying to minimize. The likelihood of a collision causing death is just as proportional to mass. A semi hauling a trailer cannot stop in a short enough distance to prevent some collisions, and can be deadly even at very low speed. Even so, we realize the impracticality of reducing mass, so we focus on speed instead. The real problem we need to focus on is collision prevention, not collision mitigation. Let's stop ignoring the reality of "bad fate", and do real work to minimize it's occurrence instead.

sliverstorm 9y ago
Reducing speeds is a form of collision prevention, is it not? A typical car can just about stop on a dime at 15mph, and a pedestrian has more time to react. There's a whole slew of other pedestrian-friendly street design that we could & should adopt as well, but that doesn't make speed any less of a valid approach.
- hermitdev 9y ago
  Speed, in of itself, is not dangerous. What is more dangerous on highways is differential speed. i.e. if you're driving 60 mph when the traffic around you is doing 80 mph, you're the problem. Probably exponentially so if you're driving slowly in the "fast" lane. While rarely enforced, most states in the US have laws that require you to pull to the right if you're impeding traffic (usually defined as holding up +2 vehicles behind you) - even if you're doing the speed limit. Yet, these laws are rarely enforced, just like "No Trucks Left 2 Lanes" is never enforced in & around Chicago, despite being posted every mile or so on I 294. I'd wager, also, that speed itself is rarely the direct cause of an accident. High speed, though, will make an accident more severe. My bet is that distracted driving is the #1 cause of accidents. On my daily 2-hour round trip on Chicagoland highways, I usually see 4-6 accidents each involving >2 cars. The shear amount of people I see on their phones is staggering. Hard to tell if it's social media or texting, but you can always tell because their head is staring at their lap, or they're holding their phones at the top of the steering wheel for all to see. I also see people with their phones mounted on their dashes watching movies or TV shows. Playing with your phone while driving is far more dangerous than paying attention & speeding.

mulmen 9y ago

Even if your claim is true it's still not the point of the article.

labster 9y ago
The point of the article is wrong, though. Anyone could have done it. All of us drivers could have killed Brian. We just weren't the unlucky ones. But it is not just the author's fault, it is all of our faults. The road system is designed with inherent danger. The street she was driving had a high speed limit with children near the road. If we design better systems, then no one has to live with needless guilt. And, even better, less people die.

dahart 9y ago

Super agreed on the gist - speed limits and policy matter, if we want to reduce fatalities. But, just to clarify and double down on speed reduction -- likelihood of death is proportional to the square of velocity. Every doubling of speed is 4x more damage in a collision!