Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Friday, June 17, 2011

See a deer? Do not veer

NPR broadcast a story on Wednesday describing how white-tailed deer eat so much young vegetation they reduce forests to near-monoculture. A century ago they were rare on the East Coast; now they're multitudinous and voracious. Biologist William McShea described how a high wire fence, maintained for 21 years to hold deer at bay, shows us what we're missing.

People in West Virginia feel the impact of deer overpopulation. According to the Insurance Institute, that state's drivers are most likely to have a run-in (one chance in 45, in any given year). Hawaiian drivers have the least to fear from deer, with less than one chance in 10,000 per year.

Wisconsin ranks in the top ten for deer risks. Our family often sees the animals ambling near I-90 and I-94, but never so vividly as one evening two weeks ago on the way back from Chicago. I was at the wheel of our van. I glanced in the left rearview mirror to check on a passing semitrailer truck; then I looked forward. Behold: a mini-herd of four deer standing on the highway and the shoulder. I stepped on the brakes as the truck on our left dispatched one animal. Our van zipped between two other animals.

So we lucked out.

Nationwide, 1.5 million cars and trucks collide with a hoofed animal every year, mostly of the deer variety, leading to an average of 150 human fatalities. 

Motorcycle riders are disproportionately at risk. Motorcyclists have deer collision rates ten times higher than what would be expected from the number of bikes on the road compared to cars.

Whistles were all the rage ten years ago. According to this bulletin
from the Insurance Institute for Highway Safety,
"The ineffectiveness of another approach — deer whistles attached to cars — has been proven. Available for more than 20 years, whistles produce ultrasonic noise (16 to 20 kHz) when a vehicle exceeds about 30 mph. The presumption is that deer will hear the noise and be warned away. It’s unclear whether deer do hear the noise, but in any event studies show the devices have no effect on deer behavior."
I was surprised to read that deer hurtle through a windshield only five percent of the time. If this happens the most common injuries are around the face. Major damage to the upper spine is possible.
There are cases of a deer passing completely through a car's passenger compartment: in the front window, out the back.

Odds of a deer collision are 30 times higher shortly after sunset than at mid-day.

Swerving at high speed in an attempt to drive around them is a dangerous tactic. It helps explain why almost half of deer-incident injuries come from the driver losing control and crashing the car, not from hitting a deer. The safest response to a deer ahead is to slow down while staying in your lane. 

And wear your seat belt, given all the injuries and fatalities attributable to high-speed impacts and rollovers.

We drivers like to think that our vehicles are fully stable and under control at highway speeds. Yes, they appear that way most of the time, but stability can be lost very quickly, particularly for vehicles that have a high center of gravity (think SUVs) or that are towing trailers. I witnessed an example fifteen years ago. While driving along an interstate in the Twin Cities, a car entering from a ramp ahead of me clipped Car No. 2 at the front bumper, forcibly redirecting it to the left. Car No. 2 swerved and hit the median barrier with a cloud of dust and fragments. It bounced off and crossed all the lanes, barely missing Car No. 1. 
As with many life-threatening emergencies, the best time to think and plan is well before the moment of truth. Many emergencies often leave little time for deliberation ... only reaction. Whether those reactions are productive or destructive depends greatly on decisions made earlier, plus smidgens of information gathered at the scene. So, decide now not to yank the steering wheel at 65 mph to avoid a deer. It's a bad idea.

Here's another example of why it's important to think about a course of action ahead of a crisis: the emergency called the sudden acceleration incident, in which a car seems to go crazy and accelerate into an obstacle or worse, a crowd. 

The majority of SAIs are due to driver mistake -- stepping on the gas instead of the brake. Others could be caused by mechanical problems. But in any case it helps to know that a fast way to interrupt an SAI is to turn the car's ignition off or put the gear selector in neutral.

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