Geometry hates cars

Source: https://twitter.com/joncstone/status/1665308737026904065

54 comments

The point he makes is correct of course, but the way he does the comparison is not very honest. If he wants to compare to the maximum capacity of a tube train, he'd also have to take the maximum capacity of a car, not the average passengers.
- But this is what happens. Every rush hour the roads are packed with cars, mostly just with one person in them, while the trains are actually full.
  
  During rush hour you definitely won't have a distance of 10 meters between each car though.
- have you seen the trains at rush hour? they are usually filled with 200% capacity.
  
  Are the tube trains always so dirty? I visited last year and that was my impression. Not the dirtiest I've seen but, yeah.
  Not meaning to criticise or anything, where I'm from we barely have functional buses, nevermind having a metro.
  
  Have you seen their rated capacity?
  They're like lifts which say they'll fit 20 people in yet even as cramped as they can get it's at most maybe 80% of that number
- No it is fair. Metros are actually completely filled many times per day. Cars almost never are.
- No, it's very honest.
  When you increase the number of passengers on a train(e.g. rush hour), the volume doesn't increase. The size of the train stays fixed up until it hits capacity.
  When you increase the number of passengers on a road, they tend to still have around 1 car/person. Encouraging people to carpool just doesn't really happen. So an "at capacity" road still has most cars with just the driver. This is one of the main reasons cars are so inefficient, people are lugging around capacity for 5 people and tons of cargo, but it never gets used even when the roads are "at capacity".
- The comparison is completely honest. It is dishonest to pretend that trains aren’t generally full and a line up of cars ever are.
  
  Trains are generally at their fullest when cars are at their emptiest, during commuter hours. Tube trains are near empty (maybe 10-15% of capacity) for most of the day and night, whereas those who do drive at those times are likely groups of workmen or otherwise groups of people going to the same place
  
  Completely honest! All cars are at least 4.5m, especially in the city where hatchbacks like the golf (4.2m) reign supreme. And what driver doesn't love driving in bumper to bumper traffic, named for the more than two full car lengths between them and both the car in front and behind.
  Not to say that the point they are dishonestly trying to make is invalid, but this is definitely playing with assumed numbers to exaggerate the point.
- I was under the impression that the tube is consistently pretty damn close to maximum capacity at peak times. Is that wrong?
- Furthermore, 10 meters is a little high given it would be tight traffic
- No because on a busy time of the day it's not hard to reach maximum capacity or close to maximum capacity on a train. But if those individuals decided to drive they would not use their cars to maximum capacity. Or you can look at it the other way around. If people driving right now (therefore the average use) started to use the train, they would not use the train up to its average use. They would use it to its maximum capacity.
- That's not an honest comparison. A full tube train is very common. A road of cars all being full is not. That's simply ridiculous.
- A bicycle is so much more efficient than a car!
  3 people one a bike in 2m vs 3km for cars, 1 person per car, with a 1km gap between every car !
  Fuck cars, but he's pushing it too much in one direction to try and make a point.
- haha yeah with a 10meter gap between cars....
- Eh I'm not so sure I agree with that. Competent subway systems in rush hour tend to be completely full whereas cars in rush hour typically only have a single person inside. So I do believe it's an apples-to-apples comparison in the ways that actually matter.
- And also a realistic distance between cars. You think cars in London leave 10m gaps? More like 1m 🤣
- Agreed its not very honest. Transportation is about getting places, not filling roads. Average speed of the tubetrain is more than double that of cars, even without dumping all of these extra people onto the roads. After accounting for that, you would need to quadruple the length so that it can match the passenger miles.
- Totally agree. It's still almost 2 miles of cars, but that isn't nearly as impactful as saying 7.2 miles
- Yeah. I hate these bullshit comparisons.
  That train number seems to include standees at AW2 (functionally rush hour)… vs the average car.
  He includes enough braking distance between cars for a relative high speed, but none for another other train.
  The cars don’t all need to go the same route, the train does.
  “The most painful argument is a bad one for something you believe in.”
  
  At rush hour, you will see full trains and streets full of cars with only one person in each. Cars don't fill up when it gets busy, but trains do.
  There's breaking distance for 20mph traffic, and trains actually do run at 90 second intervals.
  You can change trains if the one you're on doesn't match your route, or combine it with other modes. But that isn't what this comparison is about, it's about the space they take up.
- This is extremely stupid because, to be an accurate model of the effect of congestion on rail travel, people would have to get out of their car, perform a magic trick to disappear it, and then hop into a stranger's car every time they entered a congested area.
  Given that nobody has ever done this, we can see that your comment is just bizarre mental gymnastics.
  
  I agree with your point and really want to upvote it, but to be honest the way you put it was kind of rude. I'll hold my upvote for now.

Now try adding up all the square footage parking spaces take.
For example, consider that adding a parking space to a 400 sq.ft. studio apartment — or adding two spaces to a 800 sq.ft. two-bedroom — effectively increases the total square footage by a whopping 50%. And since concrete parking decks are more expensive to build than habitable area of dwelling units, that likely represents a greater than 50% increase in costs.
And yet people unironically defend minimum parking requirements while simultaneously removed about housing costs.

Wait, 10 meters between cars ?? In traffic ?
- Not unreasonable for slow-ish city traffic. Should be more for highway speeds, sure, but he compares it to the tube and overlays the distance on London.

Sounds like it would be fun to be a tube train. At least for a little while.

You’re making a good point. However, isn’t apples to apples comparison.
Trains are better but not by the way you visualize it.
- Overlay London with roads wide enough to carry as much capacity as the tube lines underneath (and somewhere to put those cars) and see if there's any space left?
  
  houston?

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