Channel 19

Todd Dills

Why unintended acceleration isn’t a heavy-duty issue

| February 16, 2013

Megan Garber, writing on the website for the The Atlantic magazine, tells the story of a terrifying trip that began with a Frenchman’s run down to a grocery from his home in Pont-de-Mez, near Amiens. Driving a Renault Laguna specially equipped for his disability, Frank Lecerf “was going 60 miles an hour when the car’s speed dial jammed,” Garber writes.

Lecerf tried to brake. Instead of slowing, though, the car sped up — with each tap on the brake leading to more acceleration. Eventually, the car reached a speed of 125 mph — and then remained stuck there. 

For an hour,” Garber continues (emphasis hers).

The Frenchman would be stuck at 125 mph on that solid hour’s tour with a multitude of high-speed police escorts along the French coastline into Belgium, where the Renault went dry on fuel and came to rest, safely, in a roadside ditch in the town of Alveringem.

Read Garber’s full story here.

While it doesn’t appear to be the case here (press reports to date offer no clarity on it), many unintended acceleration events end up to be determined the result of that oh-so-uncontrollable of factors, “human error,” i.e. the guy with his foot on the throttle instead of the brake. However, the National Highway Traffic Safety Administration found enough evidence of problems in the technology associated with Toyota’s high-profile problems to last year propose requiring automakers to include “brake-throttle override” technology to help deal with entrapped throttles. (Download the full text of their Notice of Proposed Rulemaking here.) Essentially, the technology is as its name suggests — it would ensure brake application overrides  the throttle in all cases.

In the Notice of Proposed Rulemaking for the technology, NHTSA had this to say about incidents of unintended acceleration in heavy-duty trucks:

NHTSA’s complaint and crash data reports do not indicate a trapped pedal problem in heavy vehicles.

Trucks and buses often operate at full throttle during normal driving, and the acceleration rate of trucks and buses is significantly lower than for light vehicles. Additionally, most trucks have manual transmissions for which the clutch functions as an available countermeasure in the case of a stuck throttle in a truck.

Since there is no apparent safety need for brake-throttle override systems to apply to heavy vehicles, we are proposing that the brake-throttle override requirement would apply only to passenger cars, multipurpose passenger vehicles, trucks, and buses with GVWRs of 10,000 pounds or less. However, we seek comment on this issue, specifically any data related to pedal entrapment or similar issues where BTO might be an effective safeguard.

Have you ever experienced such a problem in your truck? If so, how did you deal with it?

Given the seeming dearth of unintended-acceleration issues among heavy vehicles, we could heap likely well-deserved accolades here on the brake/throttle-safety focus of truck and component manufacturers, but ultimately there’s probably a another simple explanation of why high-profile events have not been seen.

Not to discount any real issues you may have had, of course — ultimately, I suspect it has to do with why we call professional drivers professional.

Thoughts on it all appreciated…

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  • Dave Nichols

    anyone consider turning the key off??

  • jescott418

    Most truck drivers are more experienced in dealing with problems. Frankly much of the Toyota problems were found to be driver error. The other problem of course is the driver and the lack of common sense to just turn off the ignition. But you cannot recall stupidity.

  • David S. McQueen

    In 1995, I was driving an 18-wheeler ( COE Freightliner, not new). The engine had a mechanical throttle with a spring that was attached to the linkage. When that spring broke (we were required to carry spares), the engine would not decellerate but would run wide open. All I had to do was depress the clutch, shift into neutral and steer to the next exit where I could safely park. I think 99.9% of runaway engine stories are bogus. Anyway, shift to neutral will negate the “stuck” throttle. Never turn off the ignition as this will also kill the power assist steering.

  • jay pendergraft

    Hand throtttle linkage once jamed holding wide open acceleration. Simply pulled fuel shut off engine kill pushed in clutch, kicked out of geer and coasted to stop, fixed problem and was back down the road in les than 3 minutes. All any vehicle needs(automatic or standard) is a way to kill engine at any time while still being able to control vehicle. Turning off the engine with the key should not lock the steering.

  • jay pendergraft

    running in neutral at wide open throttle can blow some engines pronto. If so push in clutch, shut off engine and if you need power assist release clutch peddle. That will turn engine making power steering pump work.

  • David S. McQueen

    Most engines are governed to limit that happening. I didn’t claim the steering would “lock”, it would just not have power assist steering. I’ve driven a big truck without power assist; it’s doable but I don’t recommend it. strives to maintain an open forum for reader opinions. Click here to read our comment policy.