When it comes to auto safety, the most basic and seemingly simple issues are sometimes the least understood.
The auto industry invests billions of dollars each year in technology to make cars safer. Laws are passed by legislators every year with the intent to make roads safer. And experts debate endlessly about whether teens or older people should be denied some or all driving privileges.
But all this ignores some rudimentary matters, such as which foot you brake with.
It is allegedly common knowledge and taught in driver education classes that motorists should always use the right foot on the accelerator and the brake pedal.
Automakers design brake and accelerator pedals to be used with only the right foot. In fact, many drivers do something entirely different, driving with both feet, one on the brake pedal and the other on the accelerator, saying it reduces reaction time.
"Left-foot braking makes for a smoother ride for my passengers, makes backing up and executing left turns a whole lot safer," Mark Stanley, a Times reader, said in an e-mail to me. "Finally, because I brake with the left foot, I never have to worry about unintended acceleration, because there is no confusion about where my right foot should be."
Stanley is not alone.
"I came to California in the 1960s and learned to negotiate the freeways, little known in Ohio," said C.W. Bogart of Hacienda Heights. "I soon found that my foot played a dance between the accelerator and the brake quite often. In time, I got to stopping with my left foot while encountering pain in the muscle holding my toes up. Eventually, the pain went away, and I have been using this system since. Right foot on the accelerator, left foot for braking."
Or take Steve Switzer, a Southland driver who says: "I'm not talking about old folks or incompetent drivers who drag the brakes but someone like me who, when driving an automatic, uses one foot for the accelerator and one for the brake. It seems so natural and efficient to me; two pedals, two feet. But we're taught from infancy almost that it's a bad trait, enough almost to send you to jail if you're caught."
Yes, Steve, many people think you should go to jail. After I wrote about a software feature on the Porsche Cayenne that cuts off engine power if a driver has one foot on the accelerator and the other on the brake, I was hit with e-mails from people stating that anybody who drives with two feet is an idiot.
Exactly who is the authority on this matter? Well, actually, nobody. I called the National Highway Traffic Safety Administration, asking what its research shows about the safety of two-footed driving. Its chief spokesman, Rae Tyson, brushed me off, saying: "It is an aspect of driver behavior we have never evaluated."
Of course, the federal government has no responsibility for driver education. In California, the Department of Motor Vehicles, which decides who gets licensed, also has no opinion on the matter. Indeed, a pilot program to set up a driver education curriculum avoids the issue.
In my search for somebody who has given two seconds' thought to this issue, I called Fast Track High Performance Driving School, which trains race car drivers in Harrisburg, N.C.
Sheldon Holman, general manager and an instructor, says many professional race car drivers use both feet or a one-footed maneuver in which they toe the brake and use the heel on the accelerator. Admittedly, these drivers are some of the best-trained drivers around, but do they ever get confused doing this?
"I am not going to say you can't get confused," Holman said. "Sometimes, the repetition of going around an oval track gives you brain fade."
Sounds like a day on the L.A. freeway system.
But opponents of two-footed driving should remember that every motorist does not have equal physical abilities and needs vary. In a 2002 study funded by the Arthritis Foundation of individuals who had had hip replacement surgery, 6% of the respondents said they had adopted two-footed driving after surgery to avoid the pain associated with moving one leg back and forth.
General Motors human factors engineer Brian Kulie said the company lays out its pedals so that either the left or right foot can be used for braking, but the design is optimized for one-footed operation. The design is fairly standardized, with the brake pedal larger and closer to the driver than the accelerator. The brake pedal is designed large enough so that small-stature individuals, mostly women, can get two feet on the pedal in an emergency stop, Kulie said.
Paul Green, a human factors expert at the University of Michigan Transportation Research Institute, said he was not aware, off-hand, of any research on two-footed driving. But he noted that the use of both feet appears to create a "more complicated movement because it involves coordination between two legs."
The concern is that in an emergency situation, drivers will apply full force to both pedals, slowing down the vehicle, but not nearly as quickly as if the gas is cut off to the engine, he said.
The average time it takes a driver to perceive that something is wrong is about 1.8 to 2 seconds, he said, while the time it takes to move the right foot from the accelerator to the brake is about 0.2 second.
So, the benefit of having a foot already on the brake pedal may be fairly small, compared to the overall problem of mentally recognizing the need to brake.
Ralph Vartabedian can be reached at ralph.vartabedian @latimes.com.