The Knowledge

Announcer: Go behind the wheel, under the hood and beyond with Car Stuff from

Ben Bowlin: Hello, everybody. Thanks for tuning in. You know me, Ben Bowlin, video writer here at the website Got a few side gigs.

Scott Benjamin: And I'm Scott Benjamin, the auto editor here at also, and today, Ben -

Ben Bowlin: Yes?

Scott Benjamin: We've got something that you've been pretty excited about talking about for the last couple weeks, really, right?

Ben Bowlin: Chomping at the bit. Yes, sir.

Scott Benjamin: Why don't you fill us in on what's going on?

Ben Bowlin: Well, okay. Therein lies a tale. Okay, so, here's the deal. Given the state of the economy lately, I've been picking up side gigs, round housing, looking at tape and stuff.

Scott Benjamin: Sure.

Ben Bowlin: I'm in between side gigs right now. It's pretty tough to keep my girlfriend in Maseratis and Ferraris. She has a terrible habit for them. So, I'm thinking maybe I will try something new that I've never done before, and that is to be a taxi driver.

Scott Benjamin: Sounds easy.

Ben Bowlin: Yes, it does. Right, why not?

Scott Benjamin: Why not? No, it sounds - it depends on where you go, I guess, right?

Ben Bowlin: Ah, look at that.

Scott Benjamin: Ah, see? Yeah. Yeah, I know.

Ben Bowlin: You've got me.

Scott Benjamin: Now, we get it.

Ben Bowlin: Yeah, because what we are going to talk about today is something that Scott and I found in our research into taxi driving, and it is something called The Knowledge. And Scott, you want to lay it on these people? Give them the good word?

Scott Benjamin: The Knowledge. Yeah, so, it's a - really, it's a test, right?

Ben Bowlin: Yes, sir.

Scott Benjamin: The Knowledge is a test, and it's a test that's given to all London taxi cab drivers. Very intense.

Ben Bowlin: Yes. How intense, you might ask.

Scott Benjamin: How intense is it?

Ben Bowlin: I'm glad you asked, Scott. It's very difficult. Basically, to be a taxi driver in London - and you know how they have those iconic black taxis?

Scott Benjamin: Oh, yeah.

Ben Bowlin: These applicants have to find the shortest route between any two possible points in a 6-mile radius from Charing Cross. So, six miles, any given address, they have to figure it out. So, how do they do this, right? Well, like the history. When did somebody come up with the idea? The history of this test, which is actually The Knowledge of London - people just call it The Knowledge because it sounds cooler, which I totally support. The history of this test dates back to 1851 when the office that supervises this sort of thing in London, the Public Carriage Office, which is under the police department, established the standards for these carriages, which at the time, their vehicles were horse drawn hackney carriages. And this - like the last carriage got a license around 1947, the last horse driven one. Now, they've kept some of the same rules, definitely the same concept, and there are more than 20,000 black cabs in London and every one of these guys and everyone one of these women driving these things, they have to pass this enormous test where they have to learn around 25,000 streets and 1,400 landmarks.

Scott Benjamin: Holy cow. Okay, so, 25,000 streets and 1,400 landmarks. You've - the way you've laid it out here, it seems like - I understand with the numbers you're talking about, it sounds pretty complex. But initially, I thought, "Well, there are pizza delivery guys around here that do that." They can find the shortest route between A and B quickly. Even if they don't use a GPS system, they've just got the map in the pizza store there, and they find out where they're going. These guys have to know it off the top of their head, right?

Ben Bowlin: Yes.

Scott Benjamin: And it's a much greater area. It's a bigger area that we're talking about. They're not allowed to use any kind of electronic devices, right?

Ben Bowlin: No, no electronics.

Scott Benjamin: Okay, this is all in the head, in the mind, memory. I would think that this is something that they have to - you probably don't pass it the first time, right?

Ben Bowlin: No, sir. No, you do not pass it the first time. Actually, it can take four years to pass just to accumulate the knowledge.

Scott Benjamin: Four years.

Ben Bowlin: And when I say the knowledge, the information.

Scott Benjamin: Wow. Four years?

Ben Bowlin: Yes, sir. Four years, 2 to 4 years. The people who take The Knowledge are usually calling themselves Knowledge Boys or Knowledge Girls, and they have to master - the Public Carriage Office has this thing called the Blue Book, and the Blue Book contains between 320 to 400 routes, and you have to go through a 7-stage testing period where you are given - the first stage, you're given six months to learn the first couple of routes. Then the next stage, you're given - I think you learn the first 40 or so in the first six months. Then, you're given 18 months to learn the other 260 or so.

Scott Benjamin: Oh, boy.

Ben Bowlin: Then after that, once you know these runs or these routes, which they're sub-organized in a way to make it easier to memorize it, then the next stage is involved connecting these routes in different ways, so it's not always -

Scott Benjamin: Can I tell you something?

Ben Bowlin: Yes, please.

Scott Benjamin: I don't think I remember what I had for breakfast. Now, how are you supposed to remember the shortest route between A and B whenever A and B constantly change? So, you don't start at the same point all the time, so they give you - it's just a big mix. They could give you any address on any street and say, "You need to get to here. What's the fastest way?" And if you miss it by one road, you're off, right? That's it.

Ben Bowlin: Excellent question, grasshopper. Eventually, it gets to the point where they are just given two arbitrary unrelated points, and they have to know how to get there. You're exactly right. They still don't use GPS. They still don't use radio directions the way that we see a lot of cabs here in the States. And it does take a while. And you're saying you couldn't remember what you had for breakfast. I have a he ard time remembering actually the most efficient route to places that I haven't visited in a while.

Scott Benjamin: Yeah, exactly.

Ben Bowlin: Even if I know - in my opinion, Google Maps is probably the best thing to happen to my convenience and the worst thing to happen to my memory.

Scott Benjamin: Go by physical landmarks, but they may change too.

Ben Bowlin: Yeah, well, it's like -

Scott Benjamin: The big tree may fall in a lightning storm.

Ben Bowlin: And these guys have to remember these landmarks, the schools, the hospitals, the theaters, the museums. There's a list. I'm not gonna read it. It's a paragraph long.

Scott Benjamin: Oh, so this is points of interest too for tourism, right?

Ben Bowlin: Yes, for tourism, for people in trouble, for people who are just going out of the way. It's divided into two things. You're awarded a badge. The green badge is for people who are driving in the city of London - not the city of London, excuse me, in London proper. And the yellow badge is a suburban badge that's awarded to people in the greater London area.

Scott Benjamin: Okay, so, I have a question for you then.

Ben Bowlin: All right.

Scott Benjamin: All right. First of all, you should be very proud if you've passed this test, right?

Ben Bowlin: Oh, are you kidding? Yes.

Scott Benjamin: It's displayed in the vehicle, I would think.

Ben Bowlin: Um-hum.

Scott Benjamin: Okay, so, what's the point of a test like this? Why don't they just do a licensing just like any other place? Why does it have to be so specific and rigid? What's the advantage to the taxi drivers? What's the advantage of being a person who's passed The Knowledge?

Ben Bowlin: Wow, okay, this is great. This sets up the rest of the show today.

Scott Benjamin: Oh, great. I'm gonna put my feet up.

Ben Bowlin: Yeah, go ahead. You've earned it.

Scott Benjamin: See you later.

Ben Bowlin: All right. That man deserves a promotion. You're coming back, right? Scott?

Scott Benjamin: All right, I'm back.

Ben Bowlin: All right. He's back. Okay, so check it out, man. The question you're asking, yeah, why? Why would we do something, this enormous mental feat, which is essentially the amount of information you're collecting, if you add it up, is probably equivalent to some higher learning degrees? Because it's not just repetitious memorization, it's also composing new information from that.

Scott Benjamin: Like we said, it's arbitrary. Sometimes, they will give you two points within the city, and you have to go from A to B and back again.

Ben Bowlin: Yeah, which is just like a real cab ride?

Scott Benjamin: Exactly.

Ben Bowlin: And so, here are the advantages. First, the advantages for the drivers! A driver of a black cab will make more money per fare than a driver of a minicab or an illegal vehicle of some sort.

Scott Benjamin: And is there any type of rule? You may or may not know this, but they can't be painted black? Is that right?

Ben Bowlin: I don't think so. I think there is some sort of protection. But also, all the black cab drivers are self employed, and so they stand to do pretty well; whereas if you're driving a mini cab or something, you may be working for a company.

Scott Benjamin: I see. So, a portion of your money - a percentage would go to the house.

Ben Bowlin: Sure. Then, another advantage is that as we know, London is a very, very, very - three more varies? Very, very, very dense place, and as a result, it's a morass of one-way streets, ongoing construction. Have you been to London, Scott?

Scott Benjamin: No, I have not.

Ben Bowlin: As drivers used to the wide roads of the United States everywhere except for Boston - I said it - then - no, I'm kidding. They are skinny in Boston, though.

Scott Benjamin: Yes, they are. I've been there.

Ben Bowlin: Yeah, but the roads can be very, very difficult for someone who's just navigating in a rent-a-car or someone from out of town who's just driven in for the weekend, so having this sort of encyclopedia knowledge - and that is a fair word to use - allows them actually to prevent any sort of traffic jam. Traffic jams are inevitable, but if you have this small army of people who actually know exactly where they are and where they're going no matter what, as a civil engineer, that's amazing, so that's one definite benefit. There's also the benefit - you and I talk a lot about how less moving parts equals less chance of something going wrong. So, if there's less reliance on mechanical means of navigation, then when things mess up, these folks - these women and men - will be able to perform where the driver of a minicab or someone relying on GPS could not.

Scott Benjamin: I totally agree. When I first moved here - this isn't even on the same level. I know this is intense, this knowledge is intense, but when I first moved here, I took a job delivering furniture.

Ben Bowlin: Oh, yeah?

Scott Benjamin: Yeah, just to get myself here in the state. And I did it for a very short amount of time, but the owner of that furniture delivery service wouldn't allow us to use any electronic means of navigation. We had to use giant map books, and we had to know where we were at all times. The reason was that he wanted us to be able to think our way out of a problem. If that ever malfunctions and we were somewhere on the other side of the state or in another state, which happened often, we'd know where we were and we could get home, I guess, is the purpose of that. It keeps you thinking and it's, believe it or not, far more reliable than the electronic means of navigation.

Ben Bowlin: And that is - you could not have set me up any better because that is one of the strangest and most impressive things about these drivers. Scott, these drivers obviously have worked and honed their memory to a point that would be, at the very least, difficult for the average person - at the very least, super difficult. So, over this number of years, what happens? What's the craziest thing you think could happen?

Scott Benjamin: The craziest thing?

Ben Bowlin: Yeah, what's the craziest?

Scott Benjamin: Boy.

Ben Bowlin: To these drivers.

Scott Benjamin: I guess construction and, of course, accidents. Am I on the right track? Is this what you're thinking?

Ben Bowlin: You're on the - that's a crazy thing. I'm gonna give you something even crazier. I don't think it's a fair question because there's no way you could have known I was gonna ask this, right?

Scott Benjamin: Yeah.

Ben Bowlin: Okay, so, check it out.

Scott Benjamin: Volcano.

Ben Bowlin: There have been a couple of studies that have found there's a little bit of a plot twist when it comes to these taxi drivers. Researchers, such as Dr. Eleanor McGuire and a couple of other very, very smart people, actually said, "Hey, how come these taxi drivers are able to do these amazing feats of memory that would baffle the average human being?" I think the average human being can remember in short term memory like 7 to 11 random numbers.

Scott Benjamin: Yeah, that's why the phone numbers are seven numbers, right?

Ben Bowlin: Right.

Scott Benjamin: I know what it is.

Ben Bowlin: What?

Scott Benjamin: They're aliens.

Ben Bowlin: Okay, and that's the end of the show. Thanks so much for tuning in.

Scott Benjamin: I guess it right. I was right.

Ben Bowlin: You were.

Scott Benjamin: Was it an asteroid? An iceberg?

Ben Bowlin: Well, if by aliens you mean not aliens, then yes, you're right on the money. This is so clever. These scientists took magnetic scanners, took basically portable MRI technology, and hooked it up to watch the brain activity of these taxi drivers navigating through a simulation of London.

Scott Benjamin: So, they're robots.

Ben Bowlin: Well, they may very well be better. They're at least the next best thing. They found that the people's activity when driving in a simulation could be traced back to things that we've always associated with memory encoding and spatial awareness, but here's the weird part, Scott. They found that these taxi drivers' brains, the hippocampus was larger - noticeably larger - in a UK taxi driver who has taken The Knowledge.

Scott Benjamin: Is this an evolution story? Really?

Ben Bowlin: This is not - you know, it's not quite evolution because we're not talking about them passing it on to their kids. Think of it more like exercise.

Scott Benjamin: Oh.

Ben Bowlin: Like if you do a lot of pushups, you get stronger biceps. Because these guys and these women are using their memory so often, so efficiently, so proactively, what's actually happening is toward the back of their hippocampus, we're seeing an expansion coupled with a greater ability to memorize information and spatial data. Then, and here's another kicker, how do we know that there's not just some huge coincidence that big brained people just tend to be taxi drivers, right, or people with larger hippocampuses? Hippocampusi? Hippocampuses.

Scott Benjamin: Hippocampuses, I think.

Ben Bowlin: We'll find out. I'm sure someone will tell us. The way they know that there's a match there is that they took some taxi drivers who had just started. They took some that had been driving for more than three decades. The longer they had been driving and doing this set of job skills, the more advanced and more above average these parts of their brains became.

Scott Benjamin: I wonder how good they are at putting together puzzles and things like that - mazes, just other things that are not driving and not directions to and from, but something with pen and paper. I wonder how that correlates.

Ben Bowlin: Well, there's actually - there are some people - they have some pretty interesting interviews you can find online because this caused a buzz. The BCC has several pretty good stories on this phenomenon that people have been measuring. A lot of students that are interviewed - Knowledge Boys and Knowledge Girls - say that can notice their memory improving just as they are studying. The more we learn about the human brain, the more we see that - for a long time, people thought that after a certain age, after you entered adulthood past a certain threshold, your brain lost a lot of its elasticity and learning ability. We're finding that that is not as extreme a loss as we thought it was because stroke victims can re-learn. They can teach their brains to do different things - well, different parts of their brain to do different things post stroke. Then, people who have - the stories abound. There are stories about Buddhist monks meditating who have been found to have larger parts of their brain than average. This may be an example of - it's obviously an example of amazing human potential, but also - and I say this as someone who loves standardized tests - this is an example of a test that is so difficult that it physically changes you when you pass.

Scott Benjamin: That's pretty interesting.

Ben Bowlin: I'm being sensationalistic.

Scott Benjamin: No, no, after years and years and years, it does.

Ben Bowlin: After years and years. Yeah.

Scott Benjamin: So, it builds up the brain muscle. You know what else is amazing about that story?

Ben Bowlin: What's that?

Scott Benjamin: That you were able to keep your train of thought while I was coming at you with things like icebergs and volcanoes and asteroids and robots and aliends.

Ben Bowlin: I mapped out the route of the conversation and I memorized it.

Scott Benjamin: Oh, very good. Very good, very good, very good. That's an interesting test, I tell you. I had no idea that there was anything like this going on for taxicab drivers. I had no idea until you mentioned it earlier this week, and then we both kind of dug into it a little bit. Wow, and it goes all the way back to the 1850s.

Ben Bowlin: Yes, 1851.

Scott Benjamin: That's incredible to me. I just can't believe that test has been around for so long. Obviously, it's changed as new streets are added. It's probably gotten a lot more complex.

Ben Bowlin: That's what I was thinking.

Scott Benjamin: Maybe.

Ben Bowlin: It just became more difficult.

Scott Benjamin: Maybe. London's always been pretty crowded, right?

Ben Bowlin: Yes.

Scott Benjamin: It always has.

Ben Bowlin: It's a seat of civilization.

Scott Benjamin: Exactly. And I bet a lot of those streets are the same streets that were there in 1850.

Ben Bowlin: Oh, yeah, I'm sure. Yeah, I'm sure. Especially -

Scott Benjamin: If not 200 years before that.

Ben Bowlin: Right. And as Americans, a lot of people have to realize that to us, 200 years is old.

Scott Benjamin: Yeah, that's right. Yeah, that's not so old over there.

Ben Bowlin: So, driving on streets that date back hundreds of year just really boggles our minds, but apparently not those of taxi drivers. So, all the stuff we're learning about the way the human brain interacts in these things may have bearing outside of the world of taxicabs because, per this BBC article I checked out - the one that also has Dr. McGuire there - this evidence that the brain is able to physically change could have positive implications for people who have disorders such as Parkinson's.

Scott Benjamin: No kidding.

Ben Bowlin: Yeah, if we can take the ability to - if we can somehow apply this way the environment can shape the brain in someone attempting a specific skill, then really we have no idea where this could go.

Scott Benjamin: So, give them another set of information to study, another type of information, say something that interests them, not the streets of London, maybe, but allow them to memorize things in the same way, and they can strengthen the brain so that maybe they could overcome a disease, even?

Ben Bowlin: We just don't know.

Scott Benjamin: Interesting.

Ben Bowlin: We don't. We do know, though, that the outside environment affects the inner workings and the growth of the brain more than we previously thought. So, with that, I think that's about all I've got on The Knowledge.

Scott Benjamin: Very nice. Very nice.

Ben Bowlin: I guess that means it's time for some -

Scott Benjamin: Listener mail. All right, Ben. I've got a piece of mail here from Jordan. Let's see if Jordan says - Jordan's 25 years old and from Las Vegas, Nevada.

Ben Bowlin: Hey, Jordan.

Scott Benjamin: All right. Jordan says, "Hi, Scott and Ben. Just a question about the antique license plate podcast. Both of you guys agree that cars made in the '80s seem to be just a little too soon to be considered antique." Right?

Ben Bowlin: Oh, no.

Scott Benjamin: Yeah, we do.

Ben Bowlin: Are we in for a spanking on this one?

Scott Benjamin: No, I don't think so. But Jordan does say, "Do you think people in the 1970s thought some of the great classics made in the '50s and '60s were also too young to be considered antique?"

Ben Bowlin: He's absolutely correct. That's a great point.

Scott Benjamin: Could be, yeah.

Ben Bowlin: That's a great point.

Scott Benjamin: He or she.

Ben Bowlin: Or she.

Scott Benjamin: Yeah.

Ben Bowlin: Or she.

Scott Benjamin: [Inaudible] Jordan. I don't know.

Ben Bowlin: Sorry, Jordan.

Scott Benjamin: Well, either way.

Ben Bowlin: Either way.

Scott Benjamin: Jordan continues on to say that, "I would argue that you guys are prejudiced against any great vehicle that doesn't look like a cherry red '55 Chevy Bel Air, which is I think one that you called out on the show, right?

Ben Bowlin: Yeah. It stings. You got me, Jordan, fair and square.

Scott Benjamin: That's true, though. It has a classic look.

Ben Bowlin: He or she is right.

Scott Benjamin: Yeah, you're right.

Ben Bowlin: Jordan, you're right.

Scott Benjamin: And Jordan agrees that, "Having antique encompass everything from a Shelby Cobra to a Yugo is a little bit ridiculous, so maybe we should divide the license plate into categories of over 25 and Golden Age of Cars."

Ben Bowlin: That's a great idea.

Scott Benjamin: Just something to think about, so there's the Golden Age of Cars, and that's what, 1930 to '65, I think is what is defined as earlier.

Ben Bowlin: '30 - yes.

Scott Benjamin: Somewhere in there. That's a reasonable thought.

Ben Bowlin: I think that's a really fair thing to say.

Scott Benjamin: One other quick thing that Jordan mentions here, and I thought this was worth mentioning, he wonders what ever happened to wing windows. You know those little windows that are triangle shaped that you push in and blow on you?

Ben Bowlin: Yeah, I love those.

Scott Benjamin: It says, "I miss them more than any fancy climate control doodad." I also miss those. I've had those on a couple of cars, and they were great.

Ben Bowlin: I had those on an El Camino that I drove for a short amount of time. We've got another listener mail we're gonna knock out real quick.

Scott Benjamin: Great.

Ben Bowlin: All right. Okay, William from Fayetteville, Georgia, just down the way, writes in and says, "Hi, Scott and Ben. Thanks. What a great show." That's nice. You don't always have to compliment us. We'll read it -

Scott Benjamin: Oh, that's nice. Well, you don't have to always read it either, Ben.

Ben Bowlin: I know. You got me. All right.

Scott Benjamin: Oh, is your arm okay?

Ben Bowlin: From patting myself on the back?

Scott Benjamin: Ah, just kidding. Just kidding. Go ahead.

Ben Bowlin: Okay, so, William says, "Back in the day where I grew up in Maryland and Pennsylvania, our Chevrolets and VWs were turned into rust buckets in a matter of just a few years." And he's talking about the - he's gonna be talking about corrosion here. He goes, "Say what they like, there was really no way to keep a car from rusting and corroding into junk. It was unusual for a new car to make it more than three years before corrosion became evident, which meant it was already extensive. Corrosion problems did not improve until Japanese cars arrived. Honda, Toyota, Datsun, etc. were quick to address corrosion problems. "GM, Ford and Chrysler only got busy dealing with corrosion when the Japanese began eating into the car market. There are now plenty of corrosion free '80s and '90s cars on the road. Corrosion is, for the most part, really a thing of the past. I suspect younger people are totally unaware of how much a problem automobile rust and corrosion once was. It sent most cars to an early grave," - he puts in parentheses "junk yard," - "even when the drive train was still going strong." He's like, "I don't know, maybe this would be at least a partial subject of a podcast." So, I wanted to say thank you, William. We have indeed made that a partial subject of a podcast because I told my dad about this, and you would have thought I was talking to a veteran of a war that nobody won.

Scott Benjamin: Really?

Ben Bowlin: Yeah, because he said, "Oh, yeah, I remember my cars. They rusted."

Scott Benjamin: Yep. I've had the same problem.

Ben Bowlin: Really?

Scott Benjamin: Yeah.

Ben Bowlin: He spray painted his gold. That's my dad, all class.

Scott Benjamin: Yeah, very nice. I spray painted mine black. See, I think that's the way to cover it. That's what you had to do. They'd fall apart. They'd fall apart in the salt and muck in the wintertime.

Ben Bowlin: So, in the wintertime uphill in the snow both ways in your -

Scott Benjamin: There you go. No, no, specifically in the wintertime with the salt on the road. It was a terrible thing.

Ben Bowlin: We've got to get out of here, folks, but before we do, of course, if you've listened this show before, you're familiar with us saying that we want to introduce you to our Facebook page, which is Car Stuff.

Scott Benjamin: And the Twitter account, which is also Car Stuff. Let's see, we've got the blog. We've got the website with a lot of articles in the auto section - well, in every section, but check out the auto section. There's a lot of different ways you can contact us. You can even e-mail us if you want.

Ben Bowlin: And that e-mail address is?

Scott Benjamin: carstuff@howstuffworks.

comAnnouncer: For more on this and thousands of other topics, visit Let us know what you think. Send an e-mail to