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Car drivers tend to underestimate the amount of space it takes for a semi to stop. Heck, every time I load up my car or attach a trailer, it takes time to becom

Car drivers tend to underestimate the amount of space it takes for a semi to stop. Heck, every time I load up my car or attach a trailer, it takes time to become accustomed to the decreased braking performance. Drivers likely could not give an accurate estimation for how many feet it takes to do anything on the road, such as come to a stop in an SUV going 50. Given the extreme mass of a cargo train, I wouldn't be surprised if the distance figures sounded high.

cup-of-tea 8y ago
Car drivers underestimate the amount of space it takes a car to stop.
grkvlt 8y ago
> how many feet it takes to do anything on the road, such as come to a stop in an SUV going 50 Isn't knowledge of stopping distances for vehicles at various speeds and different road surface conditions a requirement for obtaining a driving license? (At least, in the UK I believe it is, and I think the Highway Code tables probably over-estimate these distances for safety purposes)
- gsnedders 8y ago
  The Highway Code tables are based on an average family car in the 1960s (IIRC) when the tables were first introduced. They're ridiculously long distances for modern cars, though AIUI the "thinking time" part is nowadays thought to be too low.
  - grkvlt 8y ago
    Still, that's not a bad thing, per se. If we underestimate based on a vaguely remembered overestimated value from the highway code based on 1960s cars, then the effects cancel out and we're basically correct for modern vehicles?
    - gsnedders 8y ago
      I /think/ I recall seeing something that claimed with longer reaction times it actually ended up worse overall. That said, I think often the bigger problem is people not realising especially in more unusual conditions (like snow in much of Britain) quite how much longer braking distances become.
- code_duck 8y ago
  Yes, but I don't think it requires or correlates to real understanding of what the distances are. I doubt that people understand how it varies with speed, or what that number of feet really looks like on the road. The process I have experienced is I read what a theoretical distance is in the booklet the state gave me for the exam, and then select their indicated answer on a multiple-choice test.

cup-of-tea 8y ago

Car drivers underestimate the amount of space it takes a car to stop.

grkvlt 8y ago

> how many feet it takes to do anything on the road, such as come to a stop in an SUV going 50 Isn't knowledge of stopping distances for vehicles at various speeds and different road surface conditions a requirement for obtaining a driving license? (At least, in the UK I believe it is, and I think the Highway Code tables probably over-estimate these distances for safety purposes)

gsnedders 8y ago
The Highway Code tables are based on an average family car in the 1960s (IIRC) when the tables were first introduced. They're ridiculously long distances for modern cars, though AIUI the "thinking time" part is nowadays thought to be too low.
- grkvlt 8y ago
  Still, that's not a bad thing, per se. If we underestimate based on a vaguely remembered overestimated value from the highway code based on 1960s cars, then the effects cancel out and we're basically correct for modern vehicles?
  - gsnedders 8y ago
    I /think/ I recall seeing something that claimed with longer reaction times it actually ended up worse overall. That said, I think often the bigger problem is people not realising especially in more unusual conditions (like snow in much of Britain) quite how much longer braking distances become.
code_duck 8y ago
Yes, but I don't think it requires or correlates to real understanding of what the distances are. I doubt that people understand how it varies with speed, or what that number of feet really looks like on the road. The process I have experienced is I read what a theoretical distance is in the booklet the state gave me for the exam, and then select their indicated answer on a multiple-choice test.