Five key fixes automakers should make now to reduce unintended acceleration

Feb 5, 2010 12:52 PM

The unintended acceleration problems at Toyota are often characterized as "glitches" or malfunctions. But a truly well designed car should protect its occupants even when something unanticipated goes wrong. Below are five designed-in safety solutions that Toyota could have used, and we think every manufacturer should adopt. Each has the potential to save lives, and taken together they could have a big impact on auto safety.

1. Engineer cars so a sustained braking force can stop a car in a reasonable distance even with the accelerator pedal fully depressed

Whether unintended acceleration is caused by a floor mat, sticking accelerator pedal, or another mechanical or electrical malfunction is immaterial. A sustained press of the brake pedal should allow the car to stop in a reasonable distance, even if the throttle is wide open. While the brakes on most vehicles can stop a speeding vehicle eventually, it can take up to 1,000 feet to do so. This is too long. One method to reduce stopping distances is "smart throttle" technology that allows the brakes to override the throttle. Toyota is adding this to its vehicle line. Other methods to limit power would be acceptable as long as the vehicle can stop within a short, predetermined distance.

2. Require a minimum distance between the gas pedal and the floorboard

Sometimes the simplest fixes have the biggest impact. Many of the Toyota complaints involved floor mats, which can trap the accelerator pedal in many vehicles. (Other cars have this problem, too. See how mats can be a serious problem in this video of a government-run test that shows exactly how the wrong floor mat can cause the accelerator pedal to stick.) Sometimes people use thick all-weather mats, ill-fitting mats, or stack one mat atop another. The hooks that hold the floor mats in place can fail, or they aren't used at all. So why not design for failure? The key is to simply allow sufficient clearance between the floorboard and the bottom of the gas pedal, no matter what position the pedal is in, so the pedal clears a floor mat despite how it's stacked, scrunched, or positioned. This mirrors the change the Toyota is proposing to retroactively make to millions of vehicles.

3. Make it simpler to turn off the engine in an emergency

Push-button ignition systems are convenient and becoming more popular, but a driver might not know how to shut off the engine in an emergency. In many Toyota vehicles, the engine is shut off with a single press of a button when parked, but when the car is moving it requires a sustained three-second push. Though that's a safety precaution to prevent an accidental engine shut-off, it's an action many owners may never guess. When we simulated an unintended acceleration at our track, our driver was unaware of the three-second rule and found that multiple pushes of the on/off button did nothing. Other manufacturers allow the engine to be shut off with two quick pushes within three seconds. That allows even a panicked person to shut the engine off, and we think all push-button ignitions should work that way.

4. Require sufficient brake pedal pressure before a car can be shifted from Park

Many unintended acceleration complaints are not high-speed runaways, but occur in parking situations. Complaints often describe a vehicle lurching unexpectedly when shifted into gear. Shift interlocks, designed to prevent this, require the driver to depress the brake pedal before shifting from Park to Drive or Reverse. However, in our experience the brake pressure required to move the lever from Park is not always sufficient to keep a vehicle at rest when put into gear, especially during a cold start when the engine's idle speed is elevated. This could surprise drivers and cause the vehicle to hit a parked vehicle, garage door, or pedestrian.

5. Simplify shifting into Neutral

If your car is accelerating out of control, hitting the brakes and shifting into Neutral is your best strategy. Finding Neutral should be intuitive and obvious. Not long ago, automatic shift levers were simple to use. But the advent of gated and electronic shifters can make finding Neutral in a panic confusing. You shouldn't have to read the owners manual to figure out how to use the shifter.

Be sure to follow Consumer Reports Cars blog (RSS) and Twitter (@CRcars) to keep up with the latest safety information and advice, also see our car safety and unintended acceleration guides.