So in the first post I said "I remember that back in Albany, my peak traffic counts were on Marin or San Pablo, about 10.3 cars per lane-minute."

But I remembered something key last night: left-turn lanes. Both streets had them. Traffic on Marin could keep flowing smoothly through an intersection because cars going left could get out of the way. But that takes space. Assuming that each direction can carry 10.3 cars a minute, that's nearly 21 cars a minute, but spread over three lanes -- two travel, one shared turn. And we're back down to 7 cars per lane minute.( Read more... )

Layman's conclusion: wide roads with little 'turbulence' can get up to 10 cars per lane-minute. More complicated streets are unlikely to get above 8, after accounting for turn lanes. This will have consequences for stuff like "is it physically possible for everyone to drive to work from here?"

I was re-reading old transit links (reminder: if someone says replacing buses with microtransit will improve ridership, you're being scammed), and specifically this post on ridership basics (or archive.org for a missing scatterplot.) It's worth reading, but a passage I don't remember from before notes that ridership can have super-linear response to density. Higher density means more potential riders, and makes driving less attractive, and may attract people who don't want to drive.

( Read more... )

A few years ago, there was a thing on Tiktok and Twitter to make fun of "white people food", like chicken breast and steamed vegetables supposedly without any spice or seasoning, even salt. At the time I got offended mostly about the "white people" generalization", noting Europe's native pungents like mustard. But. ( Read more... )

Some people: look up a recipe, follow it carefully, buying all prescribed ingredients in quantity specified.

Some people, including me at times: look up a recipe to get an idea, then wing it.

Me, tonight: "Gazpacho is blended vegetables, right? Let's blend what I have on hand and see what happens."( Read more... )

Nothing deep here, just griping about today.

Avi and I set out to the Drexel Museum of Natural History. I took Indego ebike, to not worry about leaving my bike out locked, and to keep up with him. That was mostly okay, though my bike started making rattlings sounds on the way, and 20th has so many potholes, and manholes that are deep enough to potholes. I am once again baffled by how the US goes all-in on car dependency, yet can't keep the streets smooth.( Read more... )

To leaven the negativity: the museum was decent. Nice hall of dinosaur fossils (or their casts), and a lot of good dioramas. OTOH even making a second pass, I'd basically squeezed it dry in 2-2.5 hours, and our first pass took just 1.5 hours. Is that good value for $22 full-price ticket? I doubt. Fortunately we weren't paying full price.

Logan Square was kind of nice, with its flowering bushes and water fountain, and I finally checked out the main library of Philadelphia. Was nice to be in a big library again, and I accidentally found a shelf full of bicycling books, several of which I checked out.

But Philadelphia hasn't gone in on the sort of checkout technology where you can 'turn off' a book after checking it out, so that it doesn't set off the detector. At my branch library (which has no self-checkout), the librarian gives my books to me after I've gone through the detector. At the main library, you need to have brought your printed receipt with you; I ran into a bit of trouble because I'd actually turned in some other books I checked out, to make room in my backpack for the bike books, and didn't keep the first receipt for the remaining book from the first set. Fortunately the guard decided I probably wasn't doing an elaborate scam to steal one book.

I previously talked about different bidirectional two-lane streets in Berkeley/Albany. Gilman, which was narrow, and annoying and crossable; Marin, which was wide (parking, bike, wide travel, plus turn lanes), and a high-speed stream of death. Tonight I'll talk about Christian, also two-lanes, and even narrower than Gilman since there is parking on only one side[1]. It is objectively much more crossable than Marin, but has felt more annoying than Gilman, such that on my casual walks with no destination, I will often avoid crossing it. Why should this be the case? I don't know, but some ideas. ( Read more... )

Decided today to go to the Drexel Museum of Natural History. But Avi was interested too, yet couldn't go today. Decided on the Weitzman National Museum of American Jewish History. Close enough to walk to, if I wanted a brisk 20 minute walk in dew point 20 C weather. Easy bike, but taking my bike raises concerns about leaving it locked for hours in Center City. So went to Indego bikeshare, and an ebike, partly because that's all the station had. ( Read more... )

The pricing of Philadelphia's bikeshare program is pretty weird.

One ride? A whopping $4.50 for 30 minutes; extra $0.30/min if you go over or use electric. Bus fare here is $2.50 and gets you free transfers.( Read more... )

A video yesterday reminded me of the Saudi Line proposal to build a brand new very linear city (or linear arcology, one long building) in western Arabia. I looked again at the numbers, and wow it is nuts.

170 km long.

500 m high.

200 m wide.

(Area 34 km2.)

It's supposed to be higher than it's long! Crazy. You could probably bring the cost down just by flipping those two numbers (though maybe ventilating a 500 m wide building would be a bit more challenging, I dunno.)

For minimizing trip lengths you would want a circular city, or something close like a diamond or grid. But I can see some appeal of a linear city: simplifying your high speed transport by needing just one backbone route, and keeping it easy to go outside the city into a greenbelt/preserve. (Not sure how much point to that there is in western Arabia, but anyway.) So I wondered what a saner proposal might look like.

1) drop the arcology and just go with a conventional city with streets and buildings.

2) Have the width be at least a 5 minute walk from edge to spine, so 400 meters, making it 800 meters (10 minutes) edge to edge, which avoids the need to have any cross transit. This is 4x the width, so could reduce the length from 170 km to 42 km. (Though the original proposal used the height to be very high density, which I'm kind of waving away.)

You could double the width, for a 20 minute edge-edge walk; 1.6 km x 21 km.

But since you're trying to avoid cars, you should go in for bicycles and other micromobility, at let's say 3x expected walking speed. 2.4 km edge to spine, and 4.8 x 7 km in shape... which is actually almost a square, whoops. And you'd probably need cross-transit again for the minority who can't use any form of wheels, or the larger group who don't always want to. Still, it's a city where every point is a 10 minute bike/fast powerchair ride to the central spine, at 15 km/hr.

San Francisco is actually bigger than this, so I've just discovered that SF could be way nicer than it is (granted SF has hills.)

To keep a line shape better, go back to the 10 minute width of 800 meters, triple it for bikes, now you have a 2.4 x 14 km city, and can get some real rail use out of your backbone, while it's still a 15 minute walk from the center to the edge.

Not that long ago, I read At Day's Close about pre-modern night and darkness in European light. I also have a recurrent interesting in low-tech 'fantasy' settings. All this got me wondering what candlelight is actually like, something I haven't experienced in a long time. Happily, I found that my host has 8 pillar candles in the basement, plus some long lighters, so nothing had to be purchased. ( Read more... )