Reinventing the heel

BY SALLY DOMINGUEZ

Finally car makers are taking a walk in someone else's shoes and moving towards more footwear-friendly pedals.

A few years ago, a mate and I decided to make our fortunes with a silicone driving sock we named the Foot Franger.

The Franger would sit rolled up in the door pocket, ready for use by women drivers who had kicked off their high heels to get behind the wheel. Its rubber grip would ensure their feet stuck to the pedal - something of a challenge when you're unshod.

When I sought research to determine whether such a sock would be safer driving footwear than, say, sneakers or riding boots, I came up blank. It seemed there was a lot of speculation but very little published fact on the co-operation of shoes and car pedals. My project was relegated to the backburner.

My attention was drawn to the subject again recently with Toyota's overseas recall of 4 million vehicles over concerns that floor mats in them could come unstuck and interfere with the functioning of the accelerator pedal.

I wondered how many other accidents and near-misses had been caused by unpredictable footwear, be it thongs bending under the brake pedal, mules snagging the clutch or Crocs coming off completely. Unfortunately, accident reports don't usually provide details of the footwear of drivers involved in a crash.

And the somewhat inconsistent approach of authorities doesn't help. It's legal to drive barefoot in most places but not Hong Kong. In Brazil, bare feet are considered safer than slippers and clogs.

Of course, any conversation regarding appropriate driving footwear inevitably comes to the issue of driving in heels and whether it's dangerous.

It's not illegal and apparently one in four women do it. Yet most people regard it as unsafe and no vehicle directly addresses the very different mechanical action of an angled foot and elevated ankle on the pedal.

The International Encyclopedia of Ergonomics and Human Factors suggests an accelerator pedal be angled between 35 degres and 45 degrees to control the force exerted from the driver. The force on the pedal is also controlled by the angle of thrust. The encyclopedia notes pressure feedback from the foot "can be largely masked by footwear".

Even a three-centimetre boot heel substantially changes the angle and the thrusting movement of the foot, meaning anyone, male or female, with a slight shoe incline is compromised.

So what's being done to better accommodate high heels in vehicles?

Heel guards on the driver's-side foot mats were pioneered by Carla Zampatti in her 1985 Ford Laser interior to prevent wear and tear at the back of the driver's shoe. This feature is now fairly common, suggesting many makers know women drive in heels and just haven't tweaked their engineering to suit.

But things are slowly improving.

Take the case of Ford, where adjustable pedals have come into increasing use and other innovations are planned.

The core vehicle architecture supervisor at Ford's US headquarters, Bob Coury, was the lead engineer responsible for introducing adjustable pedals to Ford vehicles via the Territory in 2003.

Adjustable pedals had been around in concept cars since the 1950s, allowing driver access into difficult and restricted cockpits. In 1971, the Maserati Bora pioneered adjustable pedals in a production car courtesy of hydraulics by Citroen. French makers ran with this trend yet oddly, movable pedal boxes remain largely an under-utilised after-market add-on for the rest of us.

Not so for Ford. The 1996 Dodge Viper had used adjustable pedals to deal with a cramped foot area and Coury rigged up a prototype electric pedal box for his boss's Mustang to demonstrate their usefulness. When the boss's shorter wife used the moveable pedals, she deemed them essential and the electric adjustable pedal box was born.

The adjustable pedal box is safer for the vertically challenged because it allows short drivers to sit further from the wheel - and the airbag - and remain in control of their vehicle.

The next step as Ford sees it is to make pedals more friendly to different shoe types.

Most companies model their pedal calculations on averages, always assuming that the driver is wearing shoes but never inputting data on the shoe other than its size.

In 2008 Ford employed a shoe industry consultant to supply it with the facts and figures normally used to stock a store: the most common sizes and the proportion of sandals to stilettos to snow boots. All the user types were then input into the database, with pick-ups weighted towards boots, and Mustangs and mini-vans deemed to be more heel-friendly vehicles.

Armed with an extensive matrix of sizes and shoe types, Ford is venturing where no other car company has gone in tailoring pedals to the reality of shoes.

If the shoe fits

-It's not just cars that are changing to suit shoes. There have been several novel shoe designs to allow women to look fashionable and drive.

-British insurer Sheila's Wheels invented the Convertible Heel based on the premise that women want to wear heels but should be driving in flat shoes. Curiously, it was never produced.

-The SoleMate is a clip-on accessory for stiletto heels that increases the surface area on their bases. This supposedly allows better control of the pedals of a car.

- © Fairfax NZ News