快猫短视频

A PEDAL that works as both an accelerator and a brake will save lives if car
makers adopt the design, according to Swedish inventor Sven Gustafsson. The idea
sounds bizarre, but officials at the Swedish National Road Administration have
already done extensive road tests and approved the device for use.

It takes longer to brake in an emergency with separate pedals, says Rickard
Nilsson at Uppsala University, who tested out Gustafsson鈥檚 pedal for the SNRA.
It takes at least 0.2 seconds to move your foot from one pedal to the other, he
says, and at 90 kilometres per hour this adds five metres to your stopping
distance. Another problem with separate pedals is that it鈥檚 easy to hit the
wrong one. A slight misjudgement when going for the brake, perhaps because a
driver is wearing a new pair of shoes, can lead to the accelerator being
clipped, causing a crash.

With Gustafsson鈥檚 combined pedal you have to make two distinct motions for
accelerating and braking, and you can鈥檛 do both at the same time. To accelerate
you pivot the pedal, while to brake you push the entire pedal mechanism
forwards. So accelerating is predominantly an ankle movement, while braking
comes from extending the whole leg. 鈥淵ou can go from acceleration to braking
instantly, just by pressing the combined pedal forwards,鈥� the inventor says. 鈥淎s
soon as you brake the accelerator is switched to idle.鈥�

It鈥檚 not the first time the pedals have been rearranged. Henry Ford was the
first to introduce the three-pedal car in 1909. His Model T鈥檚 accelerator was a
lever on the steering column, while the three pedals were a brake, a gear shift
and a clutch. Ford later decided that the brake and accelerator should be placed
close to each other and operated alternately. By 1928, the Model A had an
accelerator pedal and a separate gear control. Automatic transmissions later
made the clutch obsolete.

Gustafsson, who hails from the southern Swedish city of Lund, pondered the
combined pedal idea for 30 years, but has only just got around to developing it.
Now his idea could lead to manual cars with two pedals and automatics with just
one. Since the SNRA approved it, he and his wife have been driving their car
with one鈥攚ith no problems.

During his evaluation for the SNRA, Nilsson tested how well drivers adapted
to the combined pedal. He set challenging driving tasks to assess the abilities
of 18 people before and after they drove about 1000 kilometres with the combined
pedal. They took the tests in cars with the combined pedal and with conventional
pedals. 鈥淭hey relearn very fast and without very much effort,鈥� he says. But
Nilsson is worried that drivers using the combined pedal may become accustomed
to their improved reaction time and drive more recklessly.

Besides improving normal reaction times, Nilsson believes that the combined
pedal could also make cruise control functions safer. Cruise controls allow
drivers to set a desired speed for long journeys so they can take their foot off
the accelerator and rest it. But because the combined pedal lets the driver rest
their entire foot on the pedal while cruise control is activated, they should be
able to react to emergencies far quicker.

Volvo is testing the pedal in cars, buses and trucks. But a mass-produced
version won鈥檛 be available to motorists for at least three years, even if
manufacturing approval is granted straight away.