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Physically turning your head in not a risky operation if a driver has given proper following distance to the vehicle in front. Turning to look over your sho

Physically turning your head in __not__ a risky operation if a driver has given proper following distance to the vehicle in front. Turning to look over your shoulder is only dangerous if you are driving dangerously by following too closely or at an excessive speed difference between your vehicle and surrounding traffic. My personal rule of thumb is at least 1 car length for every 10mph I'm traveling at, so at 70mph >= 7 car lengths between me and the vehicle in front of me.

bluGill 8y ago
The rule by the books is not car lengths, but two seconds. Easier to measure seconds, and cars are difference sizes so less arbitrary. 2 seconds tends to be just slightly longer than your rule. Those who study human reaction times figure that from the time something happens, you notice and you get your foot physically moved to the brake and push hard enough to make a difference 1.75 seconds have passed. Thus 2 seconds is a minimum.
- opencl 8y ago
  The one car length per 10mph rule barely gives you one second of following distance, assuming a car length is about 15 feet.
- wcarron 8y ago
  True, the rule is measured in seconds. But, I can't accurately measure time without distance. If a car passes a pole at time = 0 at ~ 60mph, I will be a certain distance behind the car if I pass the pole 2 seconds later, traveling at approximately the same speed. I find it a little easier to use distance to maintain this over time, because I can always see how far ahead of me the car is, but to measure by time takes landmarks and it's much harder to get a real accurate time measurement. In any case, I tend to err a little on the high side regarding distance for this reason.
- Noumenon72 8y ago
  The way you phrased this stuck with me, reminding me that my own response time is not all the time I need.
1123581321 8y ago
That rule of thumb gives you about a second, assuming no one cuts into your lane or crosses the median. You are reducing but not eliminating risk enough to emphasize that it’s not risky.
- wcarron 8y ago
  Yes, but it is a floor, not a ceiling. That's why I said "at least 1 car length". I give as much space as I possibly can in following distance without impeding traffic, but not less than 1cl/10mph. For example, if someone merges in front of me at approximately 3 car lengths at 65mph, I'm not going to slam on my brakes to increase the gap, then gun it back up to speed. That's dangerous. I'm going to get off the throttle, maybe brake a bit, and let the gap grow out before reapplying power, which gives me reasonable protection without endangering me too much. This is also much more predictable for cars behind me, which again is safer. Not every situation is in perfect compliance with the rules. My goal is to maximize my safety, predictability, and compliance without causing traffic problems for others. That's why it's a rule of thumb. It's not written in stone, but it's a good guideline to start.
  - 1123581321 8y ago
    Yes, but you said that turning back to look is _not_ risky and only gave one number that is too close to look back without risk. Theoretically “at least” has no upper bound, which I suppose gives you an out...
    - wcarron 8y ago
      Well I admit, I never did the math on my rule of thumb. Perhaps it's time to revise it and give even more space. Maybe I've been, despite effort, still following too closely. Like I said, I try to give maximum space and be as responsible as possible. Not perfect though. I can still improve as a driver, as your math shows.
paganel 8y ago
> Physically turning your head in __not__ a risky operation if a driver has given proper following distance to the vehicle in fron It is a very risky operation if you drive in a congested city where pedestrians can hop in front of your car at any one moment. I think that is not the case in the US but in other parts of the world if you take your eyes off from the forward-going direction then you risk hitting someone who has just appeared in front of your car out of nowhere.
dominotw 8y ago
except when someone cuts in front of you and brakes when you have ur head turned.

Physically turning your head in __not__ a risky operation if a driver has given proper following distance to the vehicle in front. Turning to look over your sho

bluGill 8y ago

The rule by the books is not car lengths, but two seconds. Easier to measure seconds, and cars are difference sizes so less arbitrary. 2 seconds tends to be just slightly longer than your rule. Those who study human reaction times figure that from the time something happens, you notice and you get your foot physically moved to the brake and push hard enough to make a difference 1.75 seconds have passed. Thus 2 seconds is a minimum.

opencl 8y ago
The one car length per 10mph rule barely gives you one second of following distance, assuming a car length is about 15 feet.
wcarron 8y ago
True, the rule is measured in seconds. But, I can't accurately measure time without distance. If a car passes a pole at time = 0 at ~ 60mph, I will be a certain distance behind the car if I pass the pole 2 seconds later, traveling at approximately the same speed. I find it a little easier to use distance to maintain this over time, because I can always see how far ahead of me the car is, but to measure by time takes landmarks and it's much harder to get a real accurate time measurement. In any case, I tend to err a little on the high side regarding distance for this reason.
Noumenon72 8y ago
The way you phrased this stuck with me, reminding me that my own response time is not all the time I need.

1123581321 8y ago

That rule of thumb gives you about a second, assuming no one cuts into your lane or crosses the median. You are reducing but not eliminating risk enough to emphasize that it’s not risky.

wcarron 8y ago
Yes, but it is a floor, not a ceiling. That's why I said "at least 1 car length". I give as much space as I possibly can in following distance without impeding traffic, but not less than 1cl/10mph. For example, if someone merges in front of me at approximately 3 car lengths at 65mph, I'm not going to slam on my brakes to increase the gap, then gun it back up to speed. That's dangerous. I'm going to get off the throttle, maybe brake a bit, and let the gap grow out before reapplying power, which gives me reasonable protection without endangering me too much. This is also much more predictable for cars behind me, which again is safer. Not every situation is in perfect compliance with the rules. My goal is to maximize my safety, predictability, and compliance without causing traffic problems for others. That's why it's a rule of thumb. It's not written in stone, but it's a good guideline to start.
- 1123581321 8y ago
  Yes, but you said that turning back to look is _not_ risky and only gave one number that is too close to look back without risk. Theoretically “at least” has no upper bound, which I suppose gives you an out...
  - wcarron 8y ago
    Well I admit, I never did the math on my rule of thumb. Perhaps it's time to revise it and give even more space. Maybe I've been, despite effort, still following too closely. Like I said, I try to give maximum space and be as responsible as possible. Not perfect though. I can still improve as a driver, as your math shows.

paganel 8y ago

> Physically turning your head in __not__ a risky operation if a driver has given proper following distance to the vehicle in fron It is a very risky operation if you drive in a congested city where pedestrians can hop in front of your car at any one moment. I think that is not the case in the US but in other parts of the world if you take your eyes off from the forward-going direction then you risk hitting someone who has just appeared in front of your car out of nowhere.

dominotw 8y ago

except when someone cuts in front of you and brakes when you have ur head turned.