Mar 22, 2010 | The Prius Syndrome

One of the more positive aspects of the recent Prius crashes (New York, Tokyo, San Diego is that intense media scrutiny has allowed Toyota to at least substantiate their claims that these were caused by driver error. Recent driver profiles include:

a) 45-year old Santee, CA, California Highway Patrol officer Mark Saylor, driving a 2009 Lexus ES 350.
b) 61-year old James Sikes, a real estate executive driving a 2008 Toyota Prius
c) 70-year old Ann Wilkins, who was driving a 2010 RAV4.
d) A 37-year-old driver driving an unspecified Toyota Prius.
e) A 77-year-old retired accountant driving a 2003 Toyota Camry.

When the LA Times did an report on runway Toyotas not too long ago, they published what they saw was 56 relevant incident reports from the NHTSA website; Megan McArdle from The Atlantic assembled the data in a nice spreadsheet). The median age for that data set was 60, with over half over the age of 60.

NPR's recent investigation suggests that Toyota isn't the only car maker to suffer from unintended acceleration incidents, though complaints to them are greatest.

Those two facts are besides the point, however.

We can always make the claim that the individuals driving these cars are highly competent, intelligent, or calm and composed enough to call 911 and that they would not be the ones pressing the gas pedal to the floor when they intend to press the brake. The problem is that there hasn't been a demonstrated proof of a car suffering from an unintended acceleration where pressing on the brakes did not slow down or completely bring the car to a halt.

Toyota engineers in California tested the 2008 Prius of James Sikes, who claimed the car accelerated out of control in March 2010.

The more interesting aspect is trying to understand what causes driver error, and what, if anything, can be done to change car design to ensure that similar mistakes don't occur as frequently. Brakes are designed to be larger than the gas pedal so that they're easier to press. Some, but not all cars, have a different spacing for the brakes and the gas pedals (the Prius, for example, has brakes that are about 2" higher off the floorboard than the gas). The general idea is that because it's harder to press, you would have to intentionally and consciously make the decision to press the gas pedal.

But with each pedal relatively close to the other, and with driver confidence such that one would expect a veteran driver to know the difference between the two, when a driver mistakenly puts their foot down on what they think to be the brake, but accelerate instead, the first reaction is not to re-evaluate the driver's conscious decision (after all, why would I make that mistake?), but to start braking even more. That's why news of the runaway Toyota's themselves are dangerous - they help proliferate the notion that there is something inherently wrong with the machine.

For example, let's say you own a perfectly functional CD player. For some odd reason one day you put the CD in upside down without realizing it. Most people will recognize that something's amiss and take a look at the CD - perhaps it's a bit dusty or scratched. At that point you'll discover your mistake. But if you've recently heard on the radio that this particular brand of CD player commonly causes problems -- there's even a recall on it -- there's an increased likelihood that you'd ascribe the lack of sound to the CD player, not yourself. After all, who would think of putting a CD upside down, right?

What could be done to solve this perennial issue? After all, Audi had a similar issue on its 1982-87 Audi 5000s, and Kia, Ford and Hondas have also had sudden unintended acceleration claims made against them. If your brain is saying "You are pressing the brakes" while your feet are flooring the gas pedal, the only clear solution is to have a radically different system to trigger a change in awareness, like having the on-board computer overtake the controls in a safe way. (The "shift to neutral idea" is good, though probably an unlikely remedy given so many things to consider when accelerating uncontrollably, whether of your own volition or not - I could however envisage an on-board computer telling the driver very loudly to do so, which might work).

Now the biggest problem is if indeed the technology is at fault, but our vision has been clouded by instances of driver error.

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