Stories
Slash Boxes
Comments

SoylentNews is people

posted by janrinok on Tuesday November 21 2017, @07:25PM   Printer-friendly
from the er-yes-no-maybe dept.

Speed cameras have been the focus of motorists' anger and frustration for years, although we are told repeatedly that they are an effective means of reducing death and injury on the roads. But is this really the case?

Whether speed cameras actually do save lives seems an easy assertion to test: measure the numbers of casualties at a site over a period, say two years; introduce a speed camera; re-measure the number of casualties over an equal period, and any reduction is due to the camera. But it's not really that simple. Many other factors are at play that might make cameras appear to be more effective than they really are. And these factors are often ignored when evaluating the performance of speed cameras at improving road safety.

Do speed cameras actually save lives?

[...] In road safety data, there is a general tendency for collision incidents at a site to reduce anyway following a short-term rise in their number, without any treatment (such as a speed camera) being applied. In statistics, this is known as regression-to-the-mean (or RTM). We also know that the long-term trend in collisions has generally been downward due to factors such as improved vehicle safety and better driver education[PDF].

So if we observe a reduction in casualties at a site following the installation of a camera, we need to ask how much of this reduction would have happened anyway (the RTM effect)? How much is due to general trends in road safety? And how much can we actually attribute to the camera itself?

[...] To make matters worse, half of the UK's fixed speed cameras may not even be turned on. So the situation is far from simple.

Methods to accurately account for RTM and trend often require knowledge of advanced statistics which may not always be available within a road safety team, and so it is likely that these confounding factors are not being considered consistently across the country.

[...] So, do speed cameras save lives? The answer is almost certainly yes, but probably not always to the extent that people are led to believe.

https://theconversation.com/do-speed-cameras-really-save-lives-87701


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 3, Interesting) by fyngyrz on Wednesday November 22 2017, @02:43AM

    by fyngyrz (6567) on Wednesday November 22 2017, @02:43AM (#600018) Journal

    So, do speed cameras save lives? The answer is almost certainly yes, but probably not always to the extent that people are led to believe.

    I don't think you can assume that.

    For instance, there's this [motorists.org], which clearly indicates people in Montana were safer when they were driving at whatever speed they were comfortable at and not worrying about getting tickets and insurance rate increases.

    Speed limits got pushed down, fatal accidents went up. There's no way around the numbers. Well, unless you're a lying, POS legislator, of course.

    Starting Score:    1  point
    Moderation   +1  
       Interesting=1, Total=1
    Extra 'Interesting' Modifier   0  
    Karma-Bonus Modifier   +1  

    Total Score:   3