Thursday, September 21, 2023


Ralph Nader and the transmission shift P-R-N-D-L sequence

Ever wonder why the sequence on your car transmission shift and many gas-powered RVs goes Park, Reverse, Neutral, Drive, then Drive 2 or Low? It is all about safety. Thank Ralph Nader.

Before 1971 it was not the law. It is now. Many vehicles, particularly General Motors and Chrysler, used P-N-D-L-R (Park, Neutral, Drive, Low, Reverse) sequence. Ralph Nader brought to attention the fact the driver had to look down at the shifter to go into low when driving. Downshifting and inadvertently going into reverse while driving was not good for safety or the transmission!

Even moving from a parked position into reverse if the transmission shift was not lifted enough vehicles could go forward instead of reverse. A huge safety issue when looking back thinking in reverse and then going forward.

Putting Neutral between Reverse and Drive was safer. U.S. manufacturers put the P-R-N-D-L sequence in effect by 1966 and it became Federal law in 1971. “Location of transmission shift positions on passenger cars. A neutral position shall be located between forward drive and reverse drive positions.”

Even now with electronic shifters, the sequence remains relatively the same. When park is a separate button, neutral still separates drive and reverse. Ferraris, Lamborghini and McLaren are all a different configuration, but it is still hard to accidentally shift into reverse when wanting to go forward.

Where is Ralph Nader for RV safety?


Nanci Dixon
Nanci Dixon
Nanci Dixon has been a full-time RVer living “The Dream” for the last six years and an avid RVer for decades more! She works and travels across the country in a 40’ motorhome with her husband. Having been a professional food photographer for many years, she enjoys snapping photos of food, landscapes and an occasional person. They winter in Arizona and love boondocking in the desert. They also enjoy work camping in a regional park. Most of all, she loves to travel.


  1. My ‘56 Plymouth 392 Hemi didn’t have a shift lever, it had push buttons, as did our ‘57 Dodge 392 Firedome Hemi and ‘63 Dodge Cornet 330 and my ‘63 Chrysler 300 Convertible.

  2. Thank you, Nanci! Very interesting. I recall the days of Nader’s Raiders and congressional testimonies about various things. You piqued my curiousity. I’ll have to do a search and see if/when Ralph Nader died and what of his career I accurately recall.

  3. “…going into reverse while driving was not good for safety or the transmission!” Nor is it good for street drag racing. I thought I was in D but was in L. I thought I was pulling it down into L but pulled it down into R. Tires squealed and the race was lost. The car? A 1957 Chev. A 50 year memory that stuck with me.

    • Too bad it wasn’t a 58 model. That was the year Chevy switched the Powerglide over to PRNDL. By the way, an errant shift into reverse would not necessarily destroy the transmission just as shifting into park when on the highway will not. The pawl mechanism is designed ratchet until the vehicle speed is low enough to safely engage it. Final comment, another reason PRNDL was adopted was to allow easier “rock cycling”, moving rapidly between drive and reverse to free a stuck situation.

  4. Ralph Nader can be rightfully credited with many things, but PRNDL is not one of them. In “Unsafe at any Speed”, PRNDL is another example Nader used to illustrate that auto manufacturers (GM in particular) did not have the safety at the top of their agenda when they introduced features in cars. Ford incorporated PRNDL in the early 50s. By the time the book was published in 1965, GM had switched Hydramatic to PRNDL in Cadillacs. It should be noted that in his book, Nader even recognized that the Corvair, on which he made his reputation, had improved its rear suspension to a much better design by 1965. His main point being that profits were emphasized over safety.

  5. Plus all vehicles in the past 20 years or so have a park lock feature. You cannot shift out of park unless you have your foot on the brake.


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