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Remove left turns for less dangerous city traffic

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Re: Remove left turns for less dangerous city traffic

#71
post #35

Earlier quoted context omitted.

If you ban cars they will be even more dead.

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.

The Unites States is not the Netherlands. If the downtown is already dying, banning cars will finish it off.

Re: Remove left turns for less dangerous city traffic

#72
post #35

Earlier quoted context omitted.

If you ban cars they will be even more dead.

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).

Re: Remove left turns for less dangerous city traffic

#73

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/

But people don’t know how to use them and just make it a free for all. Look no further than the Boston metro area for how this actually shakes out.

Re: Remove left turns for less dangerous city traffic

#74

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/

Came here to say this. Yes, it can slow down traffic in some cases but preemptively installing roundabouts in little-used intersections next to parks can save headaches of wandering kids getting flattened.

Re: Remove left turns for less dangerous city traffic

#75

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/

I'm a little skeptical that it would be safer for pedestrians and bikes. Bikes need to merge with traffic already in the roundabout instead of simply going straight through an intersection, and pedestrians would need to always check for oncoming cars rather than being able to mostly rely on lights telling them when they can cross. But then most of my experience with roundabouts is with large, multilane roundabouts so…

If you have a bike path alongside the car lanes, they seem to work really well. See this one for example - the red paved path is for bikes: https://i.redd.it/1vfvbvntky411.jpg

The bike path crosses before the point where cars merge in, so the driver's attention isn't split. Also, it may not be obvious from the picture, but the car lanes are raised to the level of the bike path where they intersect.

Re: Remove left turns for less dangerous city traffic

#76
I used to live near Boston and work in Boston. Traffic patterns there defy all logic until you think about the fact that the city was laid out before cars and so it’s not sized for cars, and definitely not delivery trucks. My suggestion is to remove cars altogether from that city. Like you aren’t allowed to drive a car into the city limits and delivery trucks are only allowed on certain days or hours (mail being treated separately). Then replace the Green line and a large number of streets with covered moving walkways and the rest with walk paths and bicycle lanes. Would the city economy suffer? Maybe. Would it be a more pleasant place to live and work? I think so.

Re: Remove left turns for less dangerous city traffic

#77

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/

I'm a little skeptical that it would be safer for pedestrians and bikes. Bikes need to merge with traffic already in the roundabout instead of simply going straight through an intersection, and pedestrians would need to always check for oncoming cars rather than being able to mostly rely on lights telling them when they can cross. But then most of my experience with roundabouts is with large, multilane roundabouts so…

Uh I live next to a roundabout (single lane) and it’s the safest thing ever. I’m guessing you’re American?

Re: Remove left turns for less dangerous city traffic

#78
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.

The biggest problem with right turns are: 1. Free rights a uncontrolled right turns that don’t protect crossing cyclists and pedestrians through time based segregation. 2. No physical/grade segregation. Cyclists become invisible in blind spots during right turns because intersections are terribly designed to support anything other than cars. A well designed intersection puts cyclists in front of cars where they are v…

I can't see this being a solution in places with lots of snow and it also takes a lot more space than the actual road.

Re: Remove left turns for less dangerous city traffic

#79

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/

But people don’t know how to use them and just make it a free for all. Look no further than the Boston metro area for how this actually shakes out.

This is a self-fulfilling prophecy. People don't know how to use them because they never encounter them. Once they've been around for a while, people will encounter them and learn how to use them.

Re: Remove left turns for less dangerous city traffic

#80

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/

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 at traffic level.

If it's the busy city center where you've got four lane surface streets intersecting with each direction having two straight through lanes, one right turn lane and one or two left turn lanes, a roundabout is never going to manage that kind of throughput by forcing all those people into a single lane to get into the roundabout at low speeds.

You may have fewer collisions, and of course very few of them will be during left turns, but you'll also reduce the utility of the roads connected to the roundabout, which will likely move traffic to other roads. Also, a collision in the roundabout stops the roundabout, which makes it hard to respond if people are injured or vehiclea disabled.

Traffic signals with 'protected' lefts don't stop people from going against the signal, but they do stop a lot of people from trying to make a gap that they really shouldn't. Sometimes a three-way signal timing pattern is appropriate; for the main direction, opposing traffic has greens for straight simultaneous (with cycles for protected left if appropriate), and for the other direction, each side gets a green for straight and left one side at a time.

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