We all are getting older, and so is our brain, which among other tasks, mediates response time and the myriad inputs involved in driving a car.
Certainly those with real disabling neurological diseases should not drive, but the vast majority of the Medicare set do not have a medical disorder at all, in spite of the forces that would like to transform the definition of such normal aging to the diagnosis of “Mild Cognitive Impairment.”
This is a major social-political issue, but this article is narrower, about how an aging population compounds the damage of the current trends in traffic design that could increase danger for us all.
I’ve focused on two issues relating to this: The first is the ubiquitous four way stop signs, and the second is the trend to roundabouts and various traffic calming devices that are more challenging to drivers, especially older ones.
This is no trivial issue as, “The National Highway Traffic Safety Administration estimates that distraction and inattention contribute to 20 to 30 percent of reported crashes.” With fatalities approaching 50,000 a year, we dare not allow decisions to be made out of habit or lack of the most serious study. Distraction is not only technology induced, but is caused by political decisions that causes a driver to check for a police car before driving quite safely at a slow speed through an unwarranted four way stop sign.
I recently sent a letter to the members of the Encinitas City Council opposing the removal of a specific traffic light that is slated to be replaced by a roundabout for these very reasons. Last week, the New York Times had an article that described exactly what I warned the council of: “The simple act of turning left … is confounded by a traffic circle, where an attempt to head east casts the driver into a ballet of choosing the proper lane, looking for the exit and maintaining a high alert in the crush of beach-seeking vehicles.”
Local municipal authorities and traffic engineering departments seem to have adopted, a bit too uncritically, the worldwide trend to transform cities that grew with the automobile into idealized villages. Roundabouts are in and traffic lights are out.
Those roundabouts that are popular usually replace four way stop signs, which are primitive as traffic control but highly effective for politically powerful communities to keep drivers from less august regions from using “their” thoroughfares. The cost in lost time and increased pollution of these signs that defy traffic-engineering standards is ignored, or they would be replaced by more effective devices that fit actual traffic patterns.
We now have little tolerance for those who text while driving, but we have yet to even acknowledge that increased complexity of a given traffic device has the same debilitating effect as answering a cell phone or other distractions.
This additional mental effort, most challenging to the increasing numbers of older drivers, may not cause a crash at the site, but increase the stress level of the driver who has an accident down the road, thus defying statistical validation of this effect.
Perhaps some day we will not have to depend on that vulnerable organ the human brain to control the complex and challenging task of driving a car, but until that time arrives driver capacity should be a major part of our approach to traffic safety.
Al Rodbell is an Encinitas resident. Visit AlRodbell.com for further references and links on this subject.
Its not that hard Al, even for old people.
You slow down when you approach the circle. If anybody’s in the circle you stop and wait. When you judge its safe to enter the circle you enter.
Go around the circle until you get to the street you want to keep going on. Exit the circle on that street.
Key to all this is slowing down when you approach the circle. Which is kind of the point of the whole thing.
The concept that older drivers face a challenge at driving in a circle at 10-15 miles an hour versus making left turns or right turns from a sideroad onto a 40-50 mph busy highway strains logic. A mistake in the first case is a fender bender, a mistake in the second serious injury or death. One function of a roundabout is traffic calming, not a treatment for increased driver anxiety or stress. Even busy two lane roundabouts record of safety for all age groups surpasses that of traffic signals with the plentiful rat runners, red light runners, right turns on any light color and high speeds.
Stress on drivers tends to coincide with the conflicts faced–traffic from multiple directions, judging left turns in face of oncoming traffic, responding to signals, etc. Most of those conflicts are erased by a roundabout thereby reducing stress and easing the driver choices.
Counter to the argument that the stress of roundabout surely must be reflected in higher crash rates after the roundabout, the evidence is to the contrary. A South Golden Road, Golden, CO study of three signalized intersection along with a signed intersection converted to four roundabouts led to between intersection speeds dropping from 48 mph to 33 mph–and crashes throughout the half mile corridor dropped.
Although the studies are yet to be made, it is expected that the more roundabouts in a community the lower the rates of crashes in the community overall–that is each roundabout reduces the crashes in adjacent areas not just at the immediate roundabout. This is exactly the French experience (they have the most roundabouts, over 30,000)–the more roundabouts built the lower the rate of walker fatalities, lower than the expected decease ascribable to the overall positive decline of walker fatalities. Over a 10 year period when roundabout population increased from 10,000 to 24,000 (1993-2003) the number of walker fatals and injuries remained fairly constant, that is, with almost two and a half times more roundabouts, the number of walker roundabout fatals remained about 2 and injures about 50. (You can see the chart by a French federal policy analyst Bernard Guichet at the 2004 Vail national roundabout conference online.)
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