3 ms·

Except for the part about the kinetic energy, your overall argument is poorly supported and seems fatally flawed. "...accidents happen when the variability of

by zeteo 16y ago

Except for the part about the kinetic energy, your overall argument is poorly supported and seems fatally flawed. "...accidents happen when the variability of speed is greatest. http://sense.bc.ca/disc/disc-09.htm http://sense.bc.ca/disc/disc-09.htm " There is nothing in the collection of short quotes, which you linked to, that supports this assertion. One of the quotes does mention speed variance, but as a possible factor, not as the proven greatest cause of accidents. Also, your analysis seems to ignore all kinds of accidents except rear-end collisions, which account for a measly 5.4% of fatal crashes in the US (http://en.wikipedia.org/wiki/Epidemiology_of_motor_vehicle_collisions http://en.wikipedia.org/wiki/Epidemiology_of_motor_vehicle_c...). In head-on collisions, run-off-road collisions, collisions with animals, collisions at intersections etc. not only does speed variability play no part, but higher speed is certain to both increase the occurrence probability and aggravate the consequences.

fleitz 16y ago
Yes, I agree that raw speed would affect those conditions you mentioned, but it's primarily a misjudging the correct speed effect and not a "speeding" effect. (eg. the correct speed was probably under the limit), therefore driving 1-2KM/h slower the rest of the time would have absolutely no effect. This is why most accidents occur under the speed limit, because people are driving under the limit but too fast for the conditions. What this study advocates is that we should drive a couple km/h slower ALL the time and what I'm saying is that we should drive faster than the limit almost ALL the time, however when conditions are bad we should drive SIGNIFICANTLY slower than the speed limit. eg. Driving 5 km/h under the speed limit on the interstate on ice won't help you, but driving 5 km/h on ice on the interstate will. Unless you get hit by someone stupidly going 100 km/h on ice, my personal ice speed record is 140km/h in Idaho, but it took me 4 miles to slow down to 20 km/h. We don't need to reduce our average speed, we need to reduce our speed greatly in very certain circumstances.
- zeteo 16y ago
  I agree with you that the speed should be much reduced in inclement weather. Other significant hazards can't be predicted as easily: drivers veering into the opposite lane; moose; debris on the road; people running red lights, etc. In all of these cases, driving a bit slower can result in significant reductions for both occurrence rate (extra reaction time) and severity (kinetic energy being proportional to v squared). The statistic that most accidents occur under the speed limit doesn't say much. (I'm not aware of the study you refer to, but I suspect a good deal of the phenomenon is due to intersection collisions.) What you want is the converse - driving under the speed limit causes most accidents (I doubt it). And even that would not be sufficient: what counts is the number of fatalities, and there are probably fewer deaths in low-speed accidents.

by zeteo 16y ago

fleitz 16y ago

Yes, I agree that raw speed would affect those conditions you mentioned, but it's primarily a misjudging the correct speed effect and not a "speeding" effect. (eg. the correct speed was probably under the limit), therefore driving 1-2KM/h slower the rest of the time would have absolutely no effect. This is why most accidents occur under the speed limit, because people are driving under the limit but too fast for the conditions. What this study advocates is that we should drive a couple km/h slower ALL the time and what I'm saying is that we should drive faster than the limit almost ALL the time, however when conditions are bad we should drive SIGNIFICANTLY slower than the speed limit. eg. Driving 5 km/h under the speed limit on the interstate on ice won't help you, but driving 5 km/h on ice on the interstate will. Unless you get hit by someone stupidly going 100 km/h on ice, my personal ice speed record is 140km/h in Idaho, but it took me 4 miles to slow down to 20 km/h. We don't need to reduce our average speed, we need to reduce our speed greatly in very certain circumstances.

zeteo 16y ago
I agree with you that the speed should be much reduced in inclement weather. Other significant hazards can't be predicted as easily: drivers veering into the opposite lane; moose; debris on the road; people running red lights, etc. In all of these cases, driving a bit slower can result in significant reductions for both occurrence rate (extra reaction time) and severity (kinetic energy being proportional to v squared). The statistic that most accidents occur under the speed limit doesn't say much. (I'm not aware of the study you refer to, but I suspect a good deal of the phenomenon is due to intersection collisions.) What you want is the converse - driving under the speed limit causes most accidents (I doubt it). And even that would not be sufficient: what counts is the number of fatalities, and there are probably fewer deaths in low-speed accidents.