General Infrastructure

Delvin4519 said:
Yes, that was what I meant from the beginning. All I remembered from the top of my head was from the NJB video that "bikes don't need traffic lights". So that's all I wrote down in the post from the start.
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There's a couple misconceptions (sometimes promoted by NJB...) around bikes, traffic lights, and intersections that I think are worth clarifying based on my experience.

  1. Bikes absolutely can cause traffic and get stuck in it if you have enough of them. There's one intersection I go through regularly (About 12 minutes in this video) where two very busy (during rush hour) cycle paths meet at a T-junction and if you need to turn onto the path that goes straight through, you might be waiting a while.
  2. Yes, Groningen has bicycle traffic lights that are green in all directions at once. It generally works fine, but I suspect only because everyone is already used to it. Rotterdam tried implementing it at some intersections and the results were much more of what you'd expect. I would not consider this to be something that could/should be ported to other cities. Even some locals agree it gets a little hairy at times.
 
TheRatmeister said:
There's a couple misconceptions (sometimes promoted by NJB...) around bikes, traffic lights, and intersections that I think are worth clarifying based on my experience.

  1. Bikes absolutely can cause traffic and get stuck in it if you have enough of them. There's one intersection I go through regularly (About 12 minutes in this video) where two very busy (during rush hour) cycle paths meet at a T-junction and if you need to turn onto the path that goes straight through, you might be waiting a while.
  2. Yes, Groningen has bicycle traffic lights that are green in all directions at once. It generally works fine, but I suspect only because everyone is already used to it. Rotterdam tried implementing it at some intersections and the results were much more of what you'd expect. I would not consider this to be something that could/should be ported to other cities. Even some locals agree it gets a little hairy at times.
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Thank you for the clarifications. Perhaps I fell into the game of telephone where some concepts get twisted ever so slightly and it turns into something slightly misleading, so these clarifcations were needed and helpful. Also helpful to note how bike lanes carry a lot more capacity than car lanes, so it only takes a handful of cars to cause gridlock, it takes more bikes to create a similar traffic jam, which most cities outside the Netherlands are nowhere near hitting that critical mass to cause bike traffic jams yet. While in the Netherlands, enough traffic is by bike instead of by car, so traffic signals there are more efficent and it's less likey there to wait 4 minutes at a red signal, like is necessary in Boston that wait times are very long to get through traffic signals. The time delay at red signals do add up signficantly.

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Delvin4519 said:
Thank you for the clarifications. Perhaps I fell into the game of telephone where some concepts get twisted ever so slightly and it turns into something slightly misleading, so these clarifcations were needed and helpful. Also helpful to note how bike lanes carry a lot more capacity than car lanes, so it only takes a handful of cars to cause gridlock, it takes more bikes to create a similar traffic jam, which most cities outside the Netherlands are nowhere near hitting that critical mass to cause bike traffic jams yet. While in the Netherlands, enough traffic is by bike instead of by car, so traffic signals there are more efficent and it's less likey there to wait 4 minutes at a red signal, like is necessary in Boston that wait times are very long to get through traffic signals. The time delay at red signals do add up signficantly.

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Oh of course, bike traffic jams are quite rare an you need an incredibly busy intersection for them to occur. But they're not impossible, and if you get enough people cycling, say a 60% mode share like in Groningen, then they do start cropping up.
 
Delvin4519 said:
Thank you for the clarifications. Perhaps I fell into the game of telephone where some concepts get twisted ever so slightly and it turns into something slightly misleading, so these clarifcations were needed and helpful. Also helpful to note how bike lanes carry a lot more capacity than car lanes, so it only takes a handful of cars to cause gridlock, it takes more bikes to create a similar traffic jam, which most cities outside the Netherlands are nowhere near hitting that critical mass to cause bike traffic jams yet. While in the Netherlands, enough traffic is by bike instead of by car, so traffic signals there are more efficent and it's less likey there to wait 4 minutes at a red signal, like is necessary in Boston that wait times are very long to get through traffic signals. The time delay at red signals do add up signficantly.

View attachment 55387
Click to expand...
Just to add a bit to what @TheRatmeister said, the requirements for traffic lights is going to depend on traffic volumes and space. You'd need many more bikes than cars (by orders of magnitude) in the same amount of space for traffic lights to start making sense. If you turned all of Boston's car space over to bikes, then yes, Boston would need vanishingly few controlled intersections. Since you posted a picture of Comm Ave, it's hard to image how many bikes you'd have to have on that road before you'd need traffic lights. Probably all of Brookline could come biking down Comm Ave every hour before you'd need lights.

Surely there is some Dutch traffic manual that says when they think certain bike volumes start to require traffic lights. I'd be curious to see what that is compared to car volumes on similar streets.

For some fun examples, here a busy intersection in Amsterdam managing alright with no traffic lights.

Something I wish I could find more info on is biking in China in the last century. Through until the late 1990s, China had virtually zero private car ownership, but the cities were filled with bikes. Any pictures or videos you can find really put the Netherlands to shame. Huge crowds of people biking with no or minimal traffic control.

Conducting traffic, Beijing, 1980s
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Rush hour in Shanghai, 1991

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TheRatmeister said:
Oh of course, bike traffic jams are quite rare an you need an incredibly busy intersection for them to occur. But they're not impossible, and if you get enough people cycling, say a 60% mode share like in Groningen, then they do start cropping up.
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Off-topic, but here are photos of legit "bike traffic jams" that I took in China:

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(Unfortunately, cars are still given priority at intersections like this. And unfortunately, most streets in China are much wider than this. It's a much more car-centric country than you may have expected.)
 
Was going to post this on the What's Going on with X thread, but not sure how visible those get, especially for the infrastructure part of this site.

Any ideas on what could be going on with the Long Island Bridge Project?

Last news article on it was that the DEP did not rule in favor of Boston's "repair" definition for the project, setting it back, which the Mayor of Quincy was seemingly jumping up and down out of joy: https://www.boston.com/news/local-news/2023/12/22/long-island-bridge-plan-not-a-repair-dep-finds-potentially-slowing-project/

This was almost a year ago at this point, and they had just posted a RFQ for a CM for the project about a year ago.
 
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