BBC News Magazine

Page last updated at 14:49 GMT, Friday, 5 February 2010

How do you stop a car with a jammed accelerator?

Speeding car

By Tom de Castella

The recall of thousands of Toyotas with potentially faulty pedals raises a terrifying hypothetical scenario - what should you do if the accelerator on your car jams?

It's a driver's worst nightmare. You try to slow down but find the accelerator pedal is stuck - you're in a runaway car.

The world's largest carmaker Toyota has recalled millions of vehicles across Europe and the US due either to the risk of accelerator pedals becoming stuck on the floor mat or jamming on their own.

Toyota insists the jamming problem is very rare and that it has only received 26 reports of any kind of problem in Europe. But stories have surfaced in recent days of Toyota drivers who have briefly experienced being out of control of their car.

In the case of the accelerator sticking, the immediate response for a lot of people would be to unjam the accelerator when the proper reaction is in fact to try to stop the car
Andrew Howard

A recording of an emergency call from a family of four who died driving a Lexus in California paints a horrifying picture.

The caller says: "We're in a Lexus… and we're going north on 125 and our accelerator is stuck… we're in trouble… there's no brakes… we're approaching the intersection… hold on… hold on and pray… pray."

It seems almost like a sequence from a film.

But however unlikely the scenario is, there is a practical question - how would you react if your accelerator became stuck?

The most important thing to do is to stay calm and not do anything rash, says Andrew Howard, head of road safety at the AA.

"The brakes will still work, the clutch will still work. The biggest problem is staying cool - as we've seen from the snowy weather people tend to panic when things start to go wrong. In a few seconds you can go into a skid and hit a tree."

Some drivers might be panicked into an unwise course of action.

1. Use the footbrake, not the handbrake
2. Depress the clutch
3. Look for a route to the side of the road, and steer there carefully
4. Only switch the engine off if the clutch cannot be used instead
5. If footbrake has failed, you can use very gentle handbrake
Source: Stephen Mead

"In the case of the accelerator sticking, the immediate response for a lot of people would be to unjam the accelerator when the proper reaction is in fact to try to stop the car," says Mr Howard. "That is the difficulty here - human nature makes it so hard to sort out these things."

For most people the place where they are driving fastest is on the motorway.

"Imagine you're driving down the inside lane of the M4 at 70 mph," says Stephen Mead, assistant chief examiner at the Institute of Advanced Motoring.

"The car ahead brakes, so you take your foot off the pedal but nothing happens. What should you do?"

It's easier said than done but Mead insists that by following a few simple steps you can quickly bring the car to a stop, saving your own and other people's lives.

If the accelerator is stuck, you should first firmly depress the foot brake, he says. This will override the accelerator.

It must be the footbrake and not the handbrake, which could cause the brake pads to burn out and potentially put the car into a spin.

Don't panic
Don't try to free the accelerator pedal
Don't waste time putting on hazard lights
Source: Stephen Mead

Next, the driver needs to depress the clutch, effectively stopping the engine from powering the car. The equivalent in an automatic car is to put the gearstick into neutral.

Continue braking and keep an eye out, forward and back, for an "escape route" to the hard shoulder. Do not try to steer straight across in one quick swerve - this could be dangerous, and destabilise the vehicle at such a speed.

In a short time - perhaps 10 seconds - you can bring the car to a halt, he says.

But what happens if the accelerator isn't the only faulty part of the car? It is very unlikely these days that the brakes will fail, as modern cars have dual brakes. There are typically two pistons controlling the brakes - if one fails you should still be able to stop the car, Mr Mead says.

But in the event the brakes do completely fail, you can still help by depressing the clutch.

Vanessa Guyll, technical specialist at the AA, argues it is easier to use the clutch to disengage the gears than to turn the key to switch the engine off.

It may be difficult at high speeds to put the car into a lower gear. So Mr Mead suggests a very gentle use of the handbrake to slow the car.

But what if the clutch has failed as well as the accelerator and brakes?

"Turn off the ignition but it's vital you leave the key there," Mr Mead says. "If you remove the key from the ignition, the steering lock will go on and that's the last thing you want."

Toyota car
Toyota has become the world's biggest car maker

If in addition to all the above, the key is also stuck, you are in the realms of the mindbogglingly unlikely.

"Then the fates are really against you," Mr Mead says. There is no ideal solution here as nothing is going to be painless, he warns. You can try and phone the police or take the car onto a grass verge or onto an HGV escape lane.

The last two are both dangerous ways of trying to slow down a car. Hitting the escape lane, designed to stop a 44-tonne truck by sinking its axle into gravel, would rip the front suspension off a car and be like hitting a brick wall, he warns.

If all else fails and there is something ahead of you that you need to avoid this might be your only option.

But all of this assumes you are on the motorway. Mr Howard says much of the same advice would apply at lower speeds on city roads, or minor roads in the countryside.

The speeds may be lower but there could be greater dangers in terms of junctions, pedestrian crossings, trees, sign and lamp posts, and closely-spaced cars.

"I'd rather it happened on the motorway in some ways," says Mr Howard. "It's not as if a few miles an hour change matters much. I wouldn't want to be approaching a zebra crossing when this happened."

Below is a selection of your comments.

For many years I worked for a leading motoring organisation on car recovery, and I can remember once where I had to recover a vehicle from the M4 with a completely wrecked engine. His car to failed to slow-down when the accelerator pedal was released but instead continued to increase speed. But the driver returned the gear lever into neutral which naturally over-revved the engine, which resulted in a catastrophic engine failure. If he'd just turned the ignition key back one click (i.e. onto the "accessory" position the engine electrics would have been isolated and he could have pulled over onto the hard shoulder in safety.
Martin, Salisbury

The advice above says "only switch the engine off if the clutch cannot be used instead". I would say definitely do not switch the engine off if you have power brakes or power steering. That would only make you more likely to lose control, as brakes and steering would become very heavy. I'd rather risk messing up the synchromesh and whack the gearstick into neutral.
Tom Purdue, Norwich

This happened to me in a Mini not long after I passed my driving test. I tried to apply the brakes to no avail, slipped the car into neutral, managed to pull into a lay-by, applied the handbrake and switched the engine off. There was a heck of a bang and it was scary not least because I had about 6 people in a 15 year old mini. But I was soon on the road again and the mini went on for another 5 years.
Caroline, West Yorkshire

The accelerator on my old Peugeot 205 became jammed in Edinburgh city centre once. Spent 10 minutes shooting around Haymarket controlling it using the clutch - I hit at least two sets of red traffic lights, where the engine's revs shot up, making a sound like a hornets' nest on wheels - until I worked out that the pedal was jammed open by a car mat. Adrenaline-pumping stuff to say the least.
Craig, Glasgow

I've never tried the HGV escape route but I do not agree with the comment expressed. The car being lighter will only become bogged down quickly if the gravel is very loose.
Jim, Ellon

Why would you 'depress' any pedals? Surely, just pressing them is how you would do it in English.
Chris, London

I myself had a very traumatic experience when driving my Yaris just over two years ago. I was gently accelerating away from a roundabout when my accelerator became stuck and the car continued to gain speed despite no pressure on the pedal. The car very quickly accelerated to speeds above 70 mph which was an extremely frightening experience for myself, I managed to use the clutch and take the car out of gear but unfortunately lost control at this point and crashed into the central reservation after the car spinning across the dual carriageway.

Luckily the oncoming traffic had stopped and I suffered minimal injuries only, a big blow to my confidence in driving was the hardest to overcome, this being my first accident in all my driving years. The outcome could have been much worse. The cause of the accident was agreed by the attending Pc and insurance inspection - it was mechanical failure.
Suzanne le Grice, Ipswich, Suffolk

I had an old Sprite a long time ago and the accelerator did once get stuck when I was driving. My fathers advice echoes that above: "When in doubt, both feet out." meaning brake and clutch together. It did work.
Jo, Portsmouth

This actually happened to me a few years ago heading north along the A1 to a friend's wedding. I agree that the natural reaction is to try to release the accelerator pedal. I reached just under 100 mph before common sense took over and I used the clutch and brake to slow. After avoiding rear-ending the car in front I did manage to free the accelerator and safely pulled off the road. Being younger, fearless and perhaps foolish, I then continued to the wedding. I soon mastered the knack of un-jamming the pedal with my toes and drove another 300 miles before eventually getting the car fixed.
Martin Heywood, Rickmansworth

Many years ago my accelerator stuck on full power in third gear when I was overtaking another car, on a single carriageway with a sharp bend approaching. Fortunately it wasn't a very powerful car so I was able to override the engine with the foot brake (had to press very hard) and just made it round the corner. The point is though, for a couple of seconds you have no idea what's happening, so don't necessarily realise you have to press the clutch. It's like some external force is pushing the car along. If I had been driving a powerful car I would have crashed for sure.
Russell Catchpole, Chichester

One point not mentioned above is that if the accelerator sticks and you depress the clutch (keeping steering and brakes working effectively) the engine will scream its head off. This will be very disconcerting but ultimately a lot better than driving flat out into a tree. Most modern cars now have a rev-limiter that will stop the engine blowing up but it will be loud and unnerving if you are not expecting it.
Phil, Ashford, Middx

I had the accelerator stick whilst driving on the M1. Approaching my exit I took my foot off the accelerator and the car began going faster rather than slowing. I did what I thought we be obvious to everyone, I turned the ignition off, then depressed the clutch and selected neutral, at the same time as braking hard. As I was already on the inside lane i then just steered onto the hard shoulder. I stopped safely and quickly inside 200 yards. No big panic, no big deal. I'm always surprised when I read of people crashing because their accelerator has stuck. Provided you have a few seconds to react, stopping is simple.
Laurie Dickerson, Worthing West Sussex

I had the accelerator pedal stick quite a few years ago on an old Astra when approaching a roundabout. It was a very scary experience accelerating towards something when you know you should be slowing down. In the end I slipped into neutral, turned off the engine and braked praying that the steering lock would not engage. Thankfully I stopped and there was no accident but it shook me up at the time.
Simon Young, Lyndhurst

I'd thought switching the ignition off to kill the engine would be the first thing to do. Using the clutch risks over-revving the engine or burning the clutch out all for the sake of a faulty accelerator pedal. With the ignition to the engine off, engine braking will slow you sufficiently and enable you to steer to the side of the road or hard shoulder. As your speed decreases then you can use the clutch and brakes to bring yourself to a controlled stop.
Dave Dyer, Eastleigh

One thing you have to accept: If it goes wrong your life is most likely forfeit. You are duty bound to ensure other peoples survival first. That might mean ramming a solid object at high speed. If it's a choice between a zebra crossing full of people, an oncoming car or a wall, pick the wall.
Leigh Ratcliffe, Slough

This happened to me in a Renault Megane a good few years back whilst on a motorway in Spain. The cable connecting the accelerator pedal to the engine frayed and caused the cable to stick with the throttle open. I slowed right down using the gears then pulled onto the hard shoulder where I took the car out of gear and stopped the car whilst instantly turning the key to stop the engine (otherwise the engine would just rev right up). Unfortunately due to my bad Spanish the use of the emergency motorway phone was rendered obsolete, and after a few calls using the phone and a good few hours waiting, I eventually had to start the car up again and drive to the nearest Renault garage. It was mid summer and I had my 10-month-old baby girl in the back of the car. We couldn't just sit indefinitely on the hard shoulder in that heat.

Thankfully the nearest Renault garage was only about 10 miles further along the motorway. It was probably the scariest 10 miles of my life.
Chris, Salisbury

I thought the last ditch inside lane of a motorway technique was to drive into the armco at a glancing angle and keep it there - scrape the speed off I know it's not ideal, but better then swerving across three lanes of traffic in search of the hard shoulder/verge (and potential solid head-on impacts) or driving into the rear of the car in front at speed. I stress - last ditch.
J-P Martins, Surrey Hills, UK

This happened to me many years ago in an old MGB, when a frayed throttle cable snagged. I simply pulled of the road (the A1) turned off the engine and stopped the car. Mildly scary at the time, but I hardly thought it life threatening.
Paul, Newcastle

This article is unbelievable - as are most of the comments. If you don't know already that the first thing you should do in this situation is turn off the engine, using the key (not all the way, of course) you shouldn't be driving. (Motorbikes have kill switches, so no need to even fumble with keys.)
Oscar, London, UK

Print Sponsor

The BBC is not responsible for the content of external internet sites

Has China's housing bubble burst?
How the world's oldest clove tree defied an empire
Why Royal Ballet principal Sergei Polunin quit


Americas Africa Europe Middle East South Asia Asia Pacific