Parallel Parking and possibly Instrumental Convergence

Fun fact: I knew someone n high school who was struggling to learn to parallel park, they called me on the phone, I explained it to them over the phone, and they passed their driving test later that day.

So yes, I think it can be taught better. I am not particularly great at it myself, and I no longer remember exactly how I was taught or what I said in that conversation. It was definitely more mathematically precise than the standard description- specific angles and alignments and the like- so not suitable for everyone's style of thinking. And those angles don't work for vehicles with terrible turning radii, like some pickups.

The standard advice people give for backing up a trailer is mostly also ridiculously bad. Relatedly, most people are bad enough at it that there are shirts about the fights it causes for couples at campgrounds. The actual process, though, is not actually hard, and there are simple descriptions and ways of communicating that accurately capture the process. My wife and I had to work those out for ourselves after watching dozens of tutorials, taking a two day driving course, and having deliberate regrouping discussions after the first few dozen attempts. This is more recent for me than learning to parallel park, so I remember it better. In this case, I think the problem is that people learning want there to be some secret that makes it easy, instead of trying to actually understand what's physically happening throughout the process. Mostly the people teaching also don't really understand why things work the way they do, and rely on repeating the magic recipe they learned.

[-]Nick_Tarleton1mo30

If one approach is simply better - why isn't everybody doing it?

Many people don't live in places where they have to parallel-park in tight spaces frequently. (Are there many people who do who don't use the better approach? I don't know.)
The better way (reversing) isn't the maximally intuitive or direct way. (I don't remember if I was ever taught it, but if so I definitely didn't internalize it and had to re-learn from experience. If I was taught it, it was when I was learning to drive, and it feels like it'd be hard to understand why it's better without more experience.)
Learned blankness, or aversion to paying enough attention to a stressful/anxious thing to learn how to do it better.

[-]CstineSublime1mo10

Thank you for linking learned blankness - that's a very interesting post just generally.

The better way (reversing) isn't the maximally intuitive or direct way.

I'm keen to see other instances where the transmission or difficulty teaching something is preventing the proliferation of a valuable and demonstrably better approach to something

[-]AnthonyC1mo20

The difficulty of learning by a given method depends in part on what prerequisites are needed to understand it, and which of those prerequisites a given student has.

[-]Richard_Kennaway1mo31

What are these two ways? Googling turns up only one (variously explained).

[-]CstineSublime1mo10

The two ways I was taught was inverted steering wheel and full lock.

I can't remember which is which, but I would assume with Full Lock, you line your car about a third of the way with the car in front, stop, turn your steering wheel as far as it will go (full lock) and then begin backing in.

The other way was you line further up, like side-mirror to side-mirror, stop, and you turn the steering wheel until it's inverted. Not full lock. And then you begin backing in.

[-]AnthonyC1mo50

FWIW, both of these approaches make assumptions about the turning radius of the vehicle you're driving and the relative lengths of the two cars that do not hold in full generality. They also differ in whether they're trying to make things fast and easy, or help you fit into tight spots. Go ahead and try to find a spot big enough to use the inverted steering wheel method in NYC, or to make people behind you wait while you do full lock in a less crowded region. It's not clear that there is one "best" method for all situations, but many teachers pretend there is because they really just want their students to pass their driving tests, at which point it is no longer their problem.

IIRC when I was learning I had 1 person explain to me that "about a third of the way" really meant "until the pillar between the passenger side windows aligns with the back of the car in front," so that your rear wheels are far enough back to guarantee that a full lock won't cause the front of your car to hit the back of theirs when you reverse to the opposite full lock later. They also explained that no one actually expects you to do it that way in real life, most of the time: It's a baseline and a guideline to help build intuition for how your car moves, and it theoretically minimizes the distance-to-curb you can achieve in any given size of spot (though the exact alignment needed for perfection does vary).

Edit to add: I'm curious if anyone has studied what methods autonomous vehicles use to parallel park, and how those compare to these standard teaching methods. I found this paper on the minimum parking size an automatic parallel parking system should need as a function of vehicle size and turning radius, but IDK if anyone has tried to map that to how humans learn.

[-]CstineSublime1mo10

I have only glanced at that paper, but it is an interesting read and the notion that it chiefly is about the space required kind of makes me reconsider my expectations of how easily this tactic could be compressed to a convergent one: maybe it just is that damn complex and comprised of so many sub-skills based on the different environments, lengths of car, and even traffic conditions.

They also explained that no one actually expects you to do it that way in real life,

My driving instructor, pointing to a space I was going to practice on stated that after I pass - I'd simply go in head-first, but that this was something that had to be mastered for the test.

[-]AnthonyC1mo20

My driving instructor, pointing to a space I was going to practice on stated that after I pass - I'd simply go in head-first, but that this was something that had to be mastered for the test.

This sounds like it assumes you'll never have to pull into a space less than a few cars lengths long. In other words, it assumes a context where the skill doesn't actually matter, and you don't need to be better at it than the bare minimum. There's no selection pressure there to converge on an optimal teaching method even if there is one.

FWIW, the official standard length of a parallel parking spot is something like 23 ft, and most passenger cars need about 1.5 car lengths of space to parallel park (though that includes however much of the spaces in front and behind happen to be available).

[-]CstineSublime1mo10

This sounds like it assumes you'll never have to pull into a space less than a few cars lengths long. In other words, it assumes a context where the skill doesn't actually matter, and you don't need to be better at it than the bare minimum.

That would be my implication not his. He wasn't saying no one ever needs to parallel park, only that he was nominating that space as a opportunity for me to practice reversing in even though I'd likely go head first in.

Honestly I don't know.

There's no selection pressure there to converge on an optimal teaching method even if there is one.

I mean it's still universal in tests, which even if it's a pointless exercise, means there is SOME selection pressure.

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2 Parallel Parking and possibly Instrumental Convergence

by CstineSublime

20th Jul 2025

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Parallel Parking and possibly Instrumental Convergence

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[-]AnthonyC1mo40

[-]Nick_Tarleton1mo30

If one approach is simply better - why isn't everybody doing it?

Many people don't live in places where they have to parallel-park in tight spaces frequently. (Are there many people who do who don't use the better approach? I don't know.)
The better way (reversing) isn't the maximally intuitive or direct way. (I don't remember if I was ever taught it, but if so I definitely didn't internalize it and had to re-learn from experience. If I was taught it, it was when I was learning to drive, and it feels like it'd be hard to understand why it's better without more experience.)
Learned blankness, or aversion to paying enough attention to a stressful/anxious thing to learn how to do it better.

[-]CstineSublime1mo10

Thank you for linking learned blankness - that's a very interesting post just generally.

The better way (reversing) isn't the maximally intuitive or direct way.

I'm keen to see other instances where the transmission or difficulty teaching something is preventing the proliferation of a valuable and demonstrably better approach to something

[-]AnthonyC1mo20

The difficulty of learning by a given method depends in part on what prerequisites are needed to understand it, and which of those prerequisites a given student has.

[-]Richard_Kennaway1mo31

What are these two ways? Googling turns up only one (variously explained).

[-]CstineSublime1mo10

[-]AnthonyC1mo50

[-]CstineSublime1mo10

They also explained that no one actually expects you to do it that way in real life,

My driving instructor, pointing to a space I was going to practice on stated that after I pass - I'd simply go in head-first, but that this was something that had to be mastered for the test.

[-]AnthonyC1mo20

My driving instructor, pointing to a space I was going to practice on stated that after I pass - I'd simply go in head-first, but that this was something that had to be mastered for the test.

[-]CstineSublime1mo10

This sounds like it assumes you'll never have to pull into a space less than a few cars lengths long. In other words, it assumes a context where the skill doesn't actually matter, and you don't need to be better at it than the bare minimum.

There's no selection pressure there to converge on an optimal teaching method even if there is one.

I mean it's still universal in tests, which even if it's a pointless exercise, means there is SOME selection pressure.

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I was taught two different ways to parallel park. I am sure there are more than just two methods. This strikes me as odd since it's a very common part of driving. Nevertheless,
I hate parallel parking and it was a constant source of anxiety when learning to drive. Apparently I'm not alone in this:

Over half (57%) of car owners surveyed report feeling stressed or anxious about parallel parking, with women and younger drivers reporting higher levels of anxiety.

Instrumental Convergence hypothesizes that sufficiently intelligent agents with similar to the same sub-goals will converge on those methods or instruments of achieving that. Parking your car parallel to the curb would appear to be one of those. Yet the methods it is done, and the methods of teaching it remain diverse despite possibly a century of hundreds of millions of drivers doing it. With such brute-force exploration strategies why have car drivers as a collective not converged on a single stress-free way to parallel park?

We can observe in nature convergent evolution. And there are many cases of multiple discovery: Both Leibniz and Newton independently arrived at Calculus is a common, but potentially controversial example of multiple independent discovery.

I have long been under impression that as a domain matures, through a combination of Mathew Effects and adopting the easier or better solution - they converge. Academy Award winner Walter Murch noted that in the early days of the car they didn't all have steering wheels, there were many different approaches to steering, braking, and acceleration until the "UI" eventually converged on three or two pedals, and a steering wheel. He made the analogy that NLE suites had converged on a single UI. Whether they converge on the best method or best UI or not is not as important as they converge on a single thing- much modern technology uses roads and wheels. A.I. research is almost certainly not at the point of convergence yet, there's still a lot of exciting techniques and methods to discover.

In microcosm learning is often the same for an individual as a whole discipline, you try out a whole lot of different approaches to something until you hit upon techniques that provide consistently acceptable results. When I was learning parallel parking I struggled to find different means of representing space, looking for different markers, turning the wheel to different degrees. And I assume through sheer trial and error I accidentally hit upon something which was more consistent.
Ya know, Babble and Prune.

So again I wonder: why was I taught two different ways to do the one - very common - thing?

Maybe not enough time has elapsed. As Orgel's Second Rule goes:

"Evolution is cleverer than you are."

So how long have people been parallel parking for?

I don't know when parallel parking was first invented. "Ranking" cars - where cars lined up in single file along the curb since the early 1900s. The first curb-side parking meters were introduced as late as 1935 - it was patented by Carl Magee and introduced to Oklahoma while he was a newspaper editor there^[1]. So parallel parking is at least 90 years old.

Is 90+ years long enough for drivers to have converged on a single method of parallel parking that consistently works (and how long will it take to converge on a single approach to teaching that best approach?). It's not just 90 years though, there's also the number of drivers and man hours spent driving.

In 2021 there were 232.8 million licensed drivers in the United States. In 2022 there were 463 million licensed car drivers in China. I was unable to find in a timely manner number of licensed drivers in the E.U. but there are 49 million "passenger cars" in Germany. One estimate puts the total "vehicle fleet" of the E.U., U.K. and EFTA at 335 million. Obviously not all these drivers and cars are being driven every day. But it does give us the ability to do a Fermi Estimate on how many man hours have gone into driving, and maybe even how much collective experience there in in Parallel Parking.

Over the course of almost 100 years over a billion people have driven a car, it is not outrageous to assume that at least 500 million of them have learned to parallel park. So why is it so hard? Why does it continue to provide such a source of anxiety for us? So much so that it is a television trope?

If one approach is simply better - why isn't everybody doing it?

Which begs the question: how do Waymos do it? And do they do it the same/differently to other self-driving cars.

It is easy to make misanthropic jokes that humans aren't intelligent agents. But even if Parallel Parking isn't a sub-goal to which agents like humans can converge, there remain numerous examples - within the automobile itself ^[2]- of convergence as domains of knowledge mature or interoperability needs force convergence.

Why can't this everyday annoyance get sorted?

^{^}
Having left Albuquerque after he was acquitted of manslaughter! His original target was a judge.
^{^}
The wheel can be compared to a killer app as it rolled over the Central Asian steps, becoming a viral hit. As Walter Murch observed, some cars were steered with levers not the steering wheel. The Internal Combustion Engine reigned supreme - albeit with many variants in numbers of cylinders and special variations like Rotary engines.