Learning to Love Your Traffic Engineer – Safety
Wednesday, November 27 by JerryFoster
Not only do traffic engineers prioritize safety lower than residents, the designs that supposedly increase safety cause more death and destruction. Why? Because motorists behave differently than engineers expect.
In 2012, there were 33,561 traffic fatalities, including 4743 pedestrians and 726 cyclists.
Traffic engineers? safety improvements include paving wider lanes and shoulders, removing roadside trees, straightening tight curves, etc.? According to AASHTO standards, ?every effort should be made to use as high a design speed as practical to attain a desired degree of safety.?
Traffic engineers believe that designing for high speed will provide safety.
The crash data, however, show ?wider lanes and shoulders were associated with statistically significant increases in crash frequencies.?
Noland reports that traditional ?road ?safety improvements? actually lead to ? increases in total fatalities and injuries,? because ?this type of approach tends to ignore behavioural reactions to safety improvements?.
Dumbaugh reports that ?a behavior-based understanding of safety performance is supported by research and literature in the field of psychology, which has focused on the subject of traffic safety as a means for understanding how individuals adapt their behavior to perceived risks and hazards.?
Marohn calls the traditional approach to safety ?professional malpractice?.
Despite WWBPA recommendations, the design for Rt 571 in downtown West Windsor follows the traditional approach – 45mph design speed, another lane and wide shoulders – all in the name of bicycle and pedestrian safety.
We?ve seen that traffic engineers might improve safety by becoming better social scientists. Before following that, however, our next installment of Learning to Love Your Traffic Engineer will look at cost.
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