Live data from Hacker News

Remove left turns for less dangerous city traffic

theconversation.com

111–120 of 174 posts

Re: Remove left turns for less dangerous city traffic

#111
post #45

Are there any stats that left turns are/how dangerous? Here most (at least the majority of media reports is about) cyclist die when a truck turns right.

That was my thought as well, when driving in city like environments, its always the cyclists on the right I need to be careful about, traffic I have to cross on the left is clearly visible, the cyclists on the right hide in a blind spot.

Re: Remove left turns for less dangerous city traffic

#112
post #95
post #80

Earlier quoted context omitted.

Roundabouts in the busy city center would be terrible. Where roundabouts fit best is in intersections with low demand, because they have low capacity, and there's no reasonable way to increase capacity. If it's the urban core busy city center where there are skyscrapers right up to the lot line, there's no room for a roundabout unless you're willing to make 'round a bumps' or carve some footprint out of the buildings…

Roundabouts can be made to handle high-traffic - supplemented by stop lights if necessary - satellite view Tijuana for some examples. The thing is until people are used to them - which can take years if not decades - they can be slower. And they can be hard to retrofit into older locations. In cities it may be better to turn streets to one way (making all turns “right turns” effectively).

Valencia, Spain is another example. I was confused in the beginning but after a day or so it felt comfortable. They have ~4 lanes in the roundabouts.

Edit: 7 lanes in this particular one: https://goo.gl/maps/HpFvtHeFTC5om81NA :o

Re: Remove left turns for less dangerous city traffic

#113
post #69

Actually to have safer cities remove cars from the traffic equation. A city without cars will be safer and cleaner for pedestrians and bikes. Air quality will also be better.

Yes please! It's unfortunate that this article and so many others focus on how we can design roads to be safer and more convenient for drivers , often requiring larger traffic control devices that make cities even more unnavigable for the rest of us. You know what's crazier the more I think about it, that the article doesn't even mention? With turn-on-red, and an abundance of intersections without dedicated left-turn…

Whew glad to find others saying the same thing. Optimizing car usage in cities is just such a painful misallocation of research effort to read about.

Only saving grace is bike roundabouts really are nice. And if we had bike lines grade separated from pedestrians everywhere[1], it could be quite fast even to the point where roundabouts are necessary because the alternative of constantly burning energy on deceleration is so annoying.

[1]: A dangerous and macho-sounding idea I nonetheless will involuntary think about every red light.

Re: Remove left turns for less dangerous city traffic

#114
My city has implemented a displaced left turn. It goes bynother names.

Traffic wanting to turn left is shunted leftwards before the main intersection. Then in its own left lane left turning traffic turns left when all other traffic goes straight except for right turns. Right turning vehicles have their own light.

Re: Remove left turns for less dangerous city traffic

#115
post #50
post #38

Earlier quoted context omitted.

I agree it’s improving from the 90s, but when I go back to the Midwest from Western Europe, the difference is dramatic simply in the number of people downtown in public spaces for cites with the same population.

That’s an extreme comparison! I bet only a few US cities would approach what you see in Berlin or Paris.

I’m not talking about Berlin or Paris. I’m taking about small European cities I’m familiar with that have vibrant walkable downtowns. Off the top of my head, Leiden Netherlands, Haarlem Netherlands, Peacara Italy, or Zug Switzerland.

Re: Remove left turns for less dangerous city traffic

#116

One of the best ways to eliminate left turns is to replace four way intersections with roundabouts. This has the advantage of working even where there isn’t a grid to facilitate the “3 right turns” strategy. For a great description of why this is so effective, see the recent freakonomics podcast: https://freakonomics.com/podcast/roundabouts/

As a pedestrian and a cyclist, please, no. I don't trust crossing a lane of traffic unless traffic is fully stopped, and nobody expects to stop in a roundabout, so I don't even feel safe using the crosswalks and hoping that the traffic will yield. Let cars come to a complete stop.

Re: Remove left turns for less dangerous city traffic

#117
post #69

Actually to have safer cities remove cars from the traffic equation. A city without cars will be safer and cleaner for pedestrians and bikes. Air quality will also be better.

And quieter. You'll often hear that cities are noisy places, but they aren't, really; it's just that cars are very loud.

Re: Remove left turns for less dangerous city traffic

#118
post #5

While I don't know of the safety impact of removing left turns, the actual trip time impact in a busy city is severely understated. In my city (700k people), an old European town, city center has seen the removal of a few key left turns in the past few years. Consequences for traffic outside city center: probably none. Consequences if you want to drive from within the city center to the outside (e.g. go back from a s…

I am biased but why do we even need cars in the city center, or at the very least why should they be convenient? Could there not be a situation where you walk to the edges of the city center to pick up your car and leave from there? There are specific accessibility concerns that certainly need to be accounted for, but the idea that the average driver loses 20 minutes on a trip that should be 5-10 minutes doesn't seem…

[deleted]

Re: Remove left turns for less dangerous city traffic

#119
post #15

Earlier quoted context omitted.

I am biased but why do we even need cars in the city center, or at the very least why should they be convenient? Could there not be a situation where you walk to the edges of the city center to pick up your car and leave from there? There are specific accessibility concerns that certainly need to be accounted for, but the idea that the average driver loses 20 minutes on a trip that should be 5-10 minutes doesn't seem…

I was waiting for this response. As someone who doesn’t live in the city center, and has no easy means of mass transportation to get there, my response is: fine I just won’t go then. You lose my money. In NYC or Chicago that’s probably not a big deal. In the vast majority of the rest of the US, that’s how you kill a city center. I can tell you in my case, given the homelessness issue that’s been getting worse the las…

This is what mid-sized American cities have been saying for about 75 years, most of which adopted this plan with zeal. And it's been a total failure. It turns out you can't save Downtown by making it easier for suburbanites to get there. Whatever you think of that approach from first principles, the evidence at this point is overwhelming. It does not work.

Re: Remove left turns for less dangerous city traffic

#120
post #35

Earlier quoted context omitted.

Not true. Go to Leiden Netherlands and see how economically vibrant a small city can become if it incentives efficient land use and limits traffic in city centre in favour of pedestrian paths an public transit.

I think you're overselling Leiden as an example of this here, isn't traffic blocked from just one main shopping street and one other (steenstraat) made somewhat hard to access? I'm not sure I would say the latter change, which was recent-ish, made a big difference versus just the general cleanup of the inner city (better train station, spruced up Beestenmarkt square etc).

Sure, there are still plenty of places you can drive in Leiden. I guess the point I’m trying to make is small cities in North America favour car transportation to an extreme. It is to the point where it’s physically dangerous to walk to some places because their aren’t even sidewalks and traffic travels much faster inside the cities than you’d ever see in the Netherlands.

Compared to small cities in North America, Leiden infrastructure is amazing — as is a lot of Dutch towns. It not that you have to completely block off all roads either. It’s just that everywhere there are roads for cars, there’s also equal space for bike and pedestrians and public transit is invested in much more. If you want to see a video series that compares the two look up the YouTube channel notjustbikes

Post reply on HN