This issue has come up tangentially in the stick shift thread, where a couple of posters have commented that using one foot for gas and one foot for the brake is dangerous.
I’m curious about that. Note that I’m putting this in GQ - I’m looking for factual evidence, one way or the other, because I’ve not been able to find it. Not opinions, or “my driving ed teacher told me”. Factual.
The only two articles I’ve been able to find in a bit of googling are a recent Vox article, which in turn cites an old LA Times article.
The Vox article is fairly lengthy, so I’m not going to quote much. The thesis is that ergonomic studies are beginning to show that a person who uses one foot for both pedals actually makes pedal errors on a regular basis, which could contribute to an accident.
The Vox article also makes the point that there are no studies that suggest that two-footed driving is more dangerous than one-footed.
The LA Times article (admittedly, from 2006), does have these interesting points:
So, what’s the Straight Dope? And again, I’m putting this in GQ because I’m not interested in opinions or anecdotes. I’m curious if there has been any reputable studies done on two-footed driving.
I have no evidence, but I find the quoted article hard to understand. When I’m driving my foot is either on the gas pedal or the brake. Even if I’m coasting at idle, my foot is lightly touching the gas pedal. I don’t see how when I’m driving I can “mistakenly put [my] foot down slightly more towards the right.” The gas pedal is where it is.
I’m curious, as well. As I noted in the other thread, I’m fairly sure that I see people out there who are using their left feet to brake, and I can tell this because their brake lights are always on (since, I’m guessing, their left feet are lightly resting on the brake pedals, but are heavy enough that the light activates).
That, of course, inserts another safety issue into the equation – if other drivers can’t tell if you’re actually braking (because the brake light is always on), does that factor introduce a different cause of accidents?
Exactly. Two-footed drivers are more likely to activate the brake switch when they’re not braking, which is essentially impossible when driving one-footed. Always having the brake lights on is dangerous. I don’t think there’s any way to argue that it’s not.
This. Similar to driving with non-functioning brake lights - the difference being that I give someone with brake lights always on a wide berth, both because I can’t tell when they are actually braking and because I suspect their driving skills. If someone has non-functioning brake lights I don’t have that warning.
I don’t think anyone can argue that driving without working brake lights isn’t dangerous. If there is a study on the increased danger of non-functioning brake lights, then that would be a reasonable upper bound on the dangers of two-footed driving (at least from the brake light perspective).
In any case, I was taught that the problem was that it is impossible to avoid light pressure on the brake pedal causing your brakes to wear out prematurely, or in the case of drum brakes increasing the chance of brake failure.
I don’t have any facts, just anecdotes and thoughts.
“pedal errors on a regular basis”:
Based on my own personal experience, the term “regular basis” seems way too frequent. I have definitely made pedal errors, but I would put them more in the rare category (once every few years) than on a regular basis.
I have gotten my foot caught behind the brake pedal a couple times in my lifetime as I was transitioning, which wouldn’t happen if I used two feet.
Regarding using two feet, I agree with the others, it tends to lead to brakes lights being on.
I’ve seen this assertion (the underlined part) several places, and while I’m admittedly a bear of very little brain I must confess that I don’t understand it. By extension, it implies that most or all manual transmission drivers — like yours truly — are constantly riding the clutch because they don’t know what else to do with their left feet.
When I’m driving an automatic transmission car, I brake with my left foot (provided the brake pedal is wide enough for my left foot to reach it easily). If this is the case, unless it’s needed for braking said foot is planted firmly on the floorboard as Og intended.
I suppose it’s entirely possible that you are, at least a little bit. And, obviously, I have no idea if there are a lot of left-foot brakers out there who aren’t riding their brakes. So, I’m not saying that all drivers who use their left feet as part of driving (manual transmission users, and left-foot brakers) are necessarily leaving their left feet on those pedals, but some clearly are. Either that, or there is a non-zero number of drivers in my area who have a short circuit in the wiring of their cars’ brake lights, causing them to be always lit.
And, of course, the difference between riding your clutch with your left foot, and riding your brake with your left foot, is that the former is completely invisible to other drivers, and not leading to a different potential safety issue.
Not directly on point but ostensibly scientific inquiry has often or usually concluded that ‘unintended acceleration’ incidents blamed on cars are actually the drivers stepping on the accelerator when they think they are stepping on the brake, with their right feet. Such as USDOT’s conclusion in Toyota case:
And my dad caused an accident where that was pretty clearly the case, was finally convinced to give up driving after that (ca. 80 yrs old).
So I think it’s well established that people can accelerate when they mean to brake when using right foot for both brake and accelerator. As to whether that’s more likely using your left foot for the brake, seems like common sense to me that it would make it even more likely. I suppose it could be one of those cases where the actual result is counter intuitive, but if there’s no clear proof in a ‘study’ it’s probably because it’s viewed as obvious.
As mentioned in the ‘stick’ thread though, using your left foot for the brake is not frowned on in all cases in all cars. Some high performance cars particularly with dual clutch automated manuals are intended to get best acceleration from a standing start in ‘launch control mode’ where you hold the car still with your left foot on the brake while flooring it with the right, transmission designed to accept that, then release the brake to go.
I don’t think I’ve ever rested my foot on a car pedal, brake or otherwise. If it’s a standard I keep my left foot to the far left until its needed. I have stood on my brake pedal with two feet at least twice. Trying to avoid collision with deer. It didnt help.
Normal standard transmission car, pickup restarting on a hill going up without a hand emergency brake takes as lot of practice to do well in each vehicle you have to drive a lot.
The release of the emergency brake sometimes is very hard to reach with your left hand while looking out for traffic, steering and trying to make a controlled start up hill.
Those who do not regularly us the emergency brake sometimes find them inoperative when needed. Automatic Transmission or standard Transmission.
Certainly not all. My car had a little spot to put your left foot when not using the clutch. Once I reached 5th gear (often going straight from third in a wind-out), my foot would be on the floor, because by that point, I would be into a highway cruise. I got into the habit, from riding a bicycle, of making my moves early by paying attention to what I was likely to be facing up ahead – when one drives like that, it tends to be a lot less stressful than riding the guy in front of you and dealing with stops at the last second.
What if brake lights were designed to reflect the intensity of the foot on pedal? A foot lightly resting on the pedal would create a dim light, but hard braking would be much brighter.
I just had to make a trip to the grocery store, in my manual transmission Mustang; halfway there, I started paying attention to what my left foot was doing.
While accelerating from a stop, and shifting from 1st to 2nd, and then from 2nd to 3rd, my left foot was hovering above the clutch pedal when I wasn’t depressing the clutch. Was I touching it a bit? Probably. Once I got to 3rd or 4th gear, and wasn’t about to shift again, my foot was moving to the “dead pedal” (that raised spot meant to act as a footrest for your left foot).
I suspect that, in stop-and-go traffic, when I’m shifting frequently, my left foot is more likely to stay above (or on) the clutch pedal, but once I’ve reached a steady speed, my left foot probably isn’t atop the pedal anymore.
I’ve thought that that would be a good idea for a long time. If everyone is slowing down as you are approaching an intersection or going up an off-ramp, then if the person in front of you suddenly starts emergency braking, it is not as obvious as if someone goes from not braking to braking.
Without the third brake light it’s already difficult enough to tell the difference between regular tail lights and brake lights on some cars. Fading in and out can be very hard to notice especially if you’re moving laterally (like changing lanes on a highway) which changes the apparent brightness of tail lights as it is by moving out of the target of the reflectors. For things like turn signals the NTSB already requires a certain minimum brightness and size that must be present the instant a “blink” starts. So for some makers that have “dynamic” signals that move in the direction of the indicated turn (not a bad idea IMO) they also require a separate non-dynamic light to meet the regs because the starting point of the dynamic light is too small to be compliant. See this Audi example: https://www.youtube.com/watch?v=OXPL1xQLhJ4 In Europe I believe the separate non-dynamic signal isn’t used, that may be just the brake light. On the Mustang each of the three signals is big enough on their own to satisfy the regs, thus they can cascade them like so https://www.youtube.com/watch?v=7SyWdmnsMfQ (let’s not argue about the combined turn signals and brake lights, that’s pretty well dealt with here: https://www.youtube.com/watch?v=O1lZ9n2bxWA ) Anyway, my point is that NTSB seems very keen on having clear abrupt changes in signals to catch the attention of other drivers, so fade-in and fade-out seems like a non-starter.
When I switch from a stick (my default) to a auto I will sometimes hit the brake when not intending to. Maybe once before it all comes back.
The manual tranny has the safety advantage over the auto in that is is easier to slow and even stop the car with just the tranny.
Over all, safety wise, I would say the stick has a slight advantage, and no disadvantage.
Can we have a link to the stick shift thread that the Op mentioned?
What happens to me, when I go to drive my wife’s Mazda CX-7, is that, when I go to start the car, my left foot instinctively goes to depress the clutch pedal – and plunges straight forward to the floor.
