Some electric cars only have one pedal - you push it up and to the right to accelerate, letting it off will decelerate - pressing it down will brake.

As long as you only use one foot to drive - then there's nothing wrong with having separate accelerator/brake pedals - but if you really want to drive, you need a clutch pedal too.

No, it should not. Controls with one function allow for better operation, and what if the one pedal malfunctioned- wouldn't you want to be able to do the opposite operation to get back to safety? If you want very simple control, stick to your video game.

Already done a few times. 'rocker pedal', press down toward top and gets throttle, release to default and slows down, press down at bottom and brakes applied. made in horizontal and vertical layout for some handicapped assist and on a few golf carts. need flexible ankle sometimes. a few riding lawnmowers have this also- hydrostat drive with single throttle pedal doing throttle and transmission speed- default with no foot is brakes applied by spring, emergency hard brake by hitting bottom of pedal to 'rock/pivot' for more brake pressure. Ford in early 1970 had a 'concept' car with the single gas/brake pedal, another with joystick control. VA contractor for modifying vehicle for amputees has kit for GM B bodies 2000 to 2005 with the rocker pedal, can be shifted left for the right leg amputees, has the separate brake pedal usually left in for alternate drivers, $200.00 and some change for a 2003 Chevy Impala for diabetic amputee. Mini Vans preferred for some handicapped with missing feet- Chryslers of early 2000 to 2012 have the space, close to same price for parts. Other makes. models have different price for parts, labor and a few not recommended for modification, some have hand controls added. minor legal problem with standardized control laws for general use- the rocker pedal is legal for special needs/ handicapped assist in USA after inspection. Your one pedal operation of down for brake, release for throttle to wide open is opposite of most single pedal units, release/loosen usually has brake applied .

So if my foot slips off the pedal my car accelerates at full throttle. Simply genius!

I believe Nissan is introducing this on one of its electric cars. Press the pedal to go, take your foot off to brake. Would be OK if you only drove that car, you would soon get used to it, but if you drove a conventional car too, it could be dangerous.

What's this with two pedals? You're thinking of a bicycle. All proper cars have three pedals

No.

You can get a car that is controlled by just one pedal -- Mattel / Fisher Price Power Wheel. Push pedal to go, remove your foot to stop. Dead easy. Usually children aged 2 can handle it.

Six-year-old children can do separate go/stop -- like a bicycle with pedals to go and hand brakes to stop.

Separate functions for go and stop is *far* safer.

Largely because the default position of the pedal being "big heavy hunk of metal moves forward" is a stupid idea.

How are you going to retrain all the current drivers safely?