Remove left turns for less dangerous city traffic | Hacker News Reader

Remove left turns for less dangerous city traffic

theconversation.com

150 pointspseudolus166 comments

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 the traffic is still pretty fast - maybe smaller roundabouts with significantly slower traffic would be safer than I'm picturing.

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.

The problem with these roundabouts is that a car driver cannot simply "exit the roundabout". They have to watch front, side and rear for cyclists. IMHO a roundabout should only ever impede traffic on entry. Once you're in the roundabout your journey around and out should be entirely unimpeded. Following the basic principles, there should never be a situation where a vehicle is going around the outter circumference of the roundabout blocking a vehicle from exiting. (Even a bicycle)

Only the front in theory: the crossing with the bicycle path is fairly close to 90 degrees. Even so -in practice- you should be checking side and rear anytime you make any turn on any kind of intersection (you fail the dutch driving exam if you forget even just once).

I agree that even ideally-er the journey out should be 100% unimpeded, but in practice this setup seems to work ok. See also video I posted for you, above. :-)

What if they moved the bike/pedestrian crossings to further along the lanes away from the roundabout? This would give more room for the cars to exit the roundabout without encountering immediate cross traffic, and more "collection space" on the exit itself so if a driver does have to stop to let a pedestrian/cyclist through they don't impede the roundabout traffic.

Posted video link of this type of roundabout in action just above ( https://news.ycombinator.com/item?id=27415631 )

There's just sufficient space for 1 car to tuck in each time.

Note that the priority here is not necessarily to maximize car throughput at all costs; but to ensure safety for all modes of traffic; and to do so inside a given amount of space and cost.

Given a different set of parameters, a different intersection type might be chosen.

(+) That said, note in the video that there's a significant number of people using the bicycle lane and pedestrian path; I think they're carrying more people than the car lanes here. I'm not a traffic expert, but forcing the denser traffic to take a longer route in favor of the less dense traffic does not seem like the right choice here. ;-)

It seems to work during that 5 minute segment, but at 1.45 it looks like this system could get gridlocked. If vehicles are blocked from exiting a roundabout for long enough, there's a risk that the whole thing will fill up. When this happens, it can only get unblocked quickly if the vehicles blocking the exits wish to leave via those exits. Edit: nope, the system can continue to move, but when more exits are blocked, the system throughput drops sharply to zero. I'd love to see this roundabout during rush hour.

For cyclists safety, this system works because the cycle lane is so far outside the vehicle lane, and it is right before pedestrian crossing. Most of the roundabouts with bicycle lanes that I have encountered, they just used a different coloured tarmac at the edge to show cyclists where they should risk their lives. They're not at 90 degrees to the cars, they're literally side-by-side. In that situation, cyclists are in greater danger of getting side-swiped by a car exiting the roundabout.

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

Proper Dutch-style roundabouts have the path for cyclists that follows the sidewalk, not the car lane.

https://commons.m.wikimedia.org/wiki/File:Alternative_dutch_...

Multi-lane intersections on major roads should just have a left-turn lane with a separate signal phase.

Unless it's a motorway-style roundabout with many multiple lanes and high velocity traffic, I much prefer to "pretend to be a car" when I cycle through roundabouts. The busiest roundabout I regularly cycle through has 2 lanes and 6 roads intersect at it. I can't imagine wanting to use it if I had to operate outside the basic rules of roundabouts.

Something like this?

https://www.youtube.com/watch?v=FR5l48_h5Eo

Mode separation for motor, bicycle, and foot traffic; all traffic crosses as close to 90 degrees as possible (for visibility reasons); priority markings on pavement; speed bump on one of the entrances to slow traffic; and a lot more features I couldn't tell you about.

( I sometimes watch https://www.youtube.com/c/NotJustBikes/ , but I'm no traffic expert )

This is incorrect. To a rounding error all the roundabouts I have encountered (in the Netherlands, where I live) have the cycle lane follow the car lane, and give cyclists right-of-way over the cars. You'll occasionally see one where the cycle lane is separated from the roundabout, but I only know of one from the top of my head.

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.

If Americans can put down their mobile phones and concentrate on the driving.

There are lots of roundabouts in the Boston area (where we call them rotaries). People encounter them regularly and STILL don't know how to use them. Although recently there have been great strides made in using lane markings to steer drivers through more effectively.

15 to 20 years ago when roundabouts were first introduced to where I live (southern Germany), people were pretty terrible at using them.

After about 5-10 years, people have gotten the hang of it, new drivers were properly educated in driving school, now they work fine.

You've got to have a little patience, and actually expose people to it, then it works out fine.

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.

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.

Many roundabouts are multilane and the design in general has higher throughput than a typical intersection because drivers don’t need to stop. Traffic is always flowing.

You are right that they require a slightly bigger footprint.

https://www.acsengineers.com.au/2016/08/22/roundabouts-vs-tr...

The biggest roundabout I’ve personally driven was an intersection of 2 freeways and a major city throughfare. 5 lanes in the circle itself, all at speeds up to 90kph.

They’ve since added stoplights on it because people were being dumb and blowing through the whole thing at ridiculous speeds.

https://images.app.goo.gl/jpzgxUyQDoqe81y38

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

CDMX as well, although some of their roundabouts move in both directions, which is both insane and appeared to be the worst of all worlds.

Reminds me of that study showing you could have computer controlled cars weave through an intersection without stopping and it worked fine but the passengers couldn’t stand it.

So devise an automated devil’s traffic circle with cars going in all directions.

There shouldn't be cars at all in busy city centers.

Cities in Europe are full of roundabouts in the busy city center, we don't have four way intersections. It's not terrible; it's safer. They handle the throughput better than intersections, because the flow is usually uninterrupted.

You should visit the UK and get a native to drive you around some city centres. We have the full range of roundabouts from massive, traffic light controlled, multi-lain and chain-linked junctions, down to tiny roundabouts that are little more than a circular bump in the road.

It's rare that I stop at a junction that requires me to cross a traffic flow, lights or no lights, that I don't wish that a roundabout had been put there instead.

Collisions can at times bring a roundabout to a halt, but more often than not, people just use common sense and move around any obstacle, while maintaining as much lain discipline as they can.

Cyclists, so long as they behave as if they are cars, also rarely have issues at roundabouts. I'm quite accustomed, in my area, to following a cyclist around a roundabout, paying attention to their hand signals, and giving them plenty of space.

Basically, it comes down to training and practice. In the UK, if you can't handle a variety of roundabouts, you'll fail your driving test.

Manchester is full of them. Majority of junctions on the M60, the motorway circling the city, have roundabouts after you come off / before you get on.

In fact, there are two roundabouts in Worsley/Walkden. Though those cause a huge amount of traffic in rush hour.

Pretty much any journey I take in the UK involves at least one and could be upwards of 10 to 20 for longer distance drives.

> I'm quite accustomed, in my area, to following a cyclist around a roundabout, paying attention to their hand signals, and giving them plenty of space.

As a cyclist, sometimes in roundabouts, this is something that many drivers need to be more aware of. In particular, depending on the roundabout size, the entry angle, and the car, someone's A pillar may completely obscure a cyclist.

Also, while a great solution for cars, in populated areas, roundabouts can be tricky for pedestrians to cross. Also not aided by the fact that at least in Germany many motorists have no clue about the exact rules (yield to crossing pedestrians and cyclists when exiting the roundabout because that's effectively a turn). The best solution in this regard still seems to be to put zebra crossings all around the roundabout, along with traffic islands between the lanes entering and existing the roundabout. That makes it sufficiently safe for people and bikes to cross and sufficiently obvious to drivers how to behave. But that takes even more space.

As a French, it's really surprising to see how other people from other countries aren't used to roundabouts. I really like how diverse roundabouts are here. Some are arranged like gardens, some have flowers, some have sculptures, some have decorations made by the local school.

A funny anecdote: we used to go to Pontarlier from time to time because our grandparents had a house here. Every time we went, we saw that [1] awful roundabout. A few years ago, it was elected as the ugliest roundabout in France.

https://france3-regions.francetvinfo.fr/image/Zb2s5pOo3hJVEK...

(Edit: I've edited the link to point the correct roundabout. The previous link was https://sf1am.autojournal.fr/wp-content/uploads/sites/9/2018...)

Is that a thumb?!

Sorry, this was the wrong link but yes this one is a thumb.

The French are not very good at using roundabouts IME, they don't indicate which exit they intend to use.

Just making sure this isn't a misunderstanding: Roundabout signaling laws and conventions vary between countries, and in some countries you're supposed to signal your intent both entering and exiting the roundabout, while in some you only signal at the exit. I'm not sure about French conventions, but in some European countries (Germany, some Eastern European countries, probably others) indicating before the roundabout is actually illegal.

French conventions are to signal when you're exiting at the next exit.

I drive in Italy and Canada, the signaling is very different. In Italy you would signal left to indicato "entering", then signal right when about to leave.

In Canada you signal before entering, and signal right when you plan to exit right, left when left, nothing when going straight.

This assumption doesn't work for Italy wherte there are roundabouts with 5 or more roads involved.

You know, it's kinda cool. If that's the worst roundabout in France...

Place de l'Etoile in Paris is one of the most famous roundabout.

http://www.champselysees-paris.com/images/sightseeing-images...

Two wrongs don't make a left, but 3 rights do.

Try that in this city :)

http://szczecinblog.pl/wp-content/uploads/2011/07/historyczn...

I've visited it a few years ago and I found myself accidently going in circles constantly :)

Round and round we go... You just wanted to take the very scenic route to make sure you didn't miss anything. ;-)

Not hard to get into that situation here if you don't know which way you are going: https://www.google.com/maps/@48.6302508,-123.4122954,275m/da...

Swindon's 7 rings of fiery death doesn't need right turns or stop lights.

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.

I think this is a pertinent point to the way roundabouts are implemented and used in North America. Cars are almost always going too fast on their exit from the roundabout, which renders the "yield" sign on the exit side crosswalks defunct. Not to mention that if they do yield to a pedestrian there, the crosswalks are close enough to the roundabout that they might be impeding traffic in the roundabout itself.

The crosswalks in the roundabout need to be moved away from the circle itself significantly (10-15m at least) for roundabouts to be safe for cyclists and pedestrians. At least for the way they are used in North America IME.

It depends a lot on the country you are in. In the Netherlands pedestrians and cyclists normally get priority, because the car is making a right turn while the other groups are continuing in a straight fashion. What probably also helps is that when a car is involved in an accident with a pedestrian/cyclist the default assumption is that the car driver is guilty.

My lengthy driving experience in and around the New York area has more than convinced me that widespread inability to merge would make roundabouts here extremely difficult to implement. The few that do exist are usually littered with people who have stopped completely or are trying to cut across three lanes of traffic because they don't know what they are doing or where they are going.

Roundabouts are great when people know how to use them to their full effect. They are beginning to become more common in the US but no one knows how to use them. People will treat it like a four way intersection until it is completely empty. Drives me nuts.

I live close to a place that has only roundabouts and zero intersections. It's just terrible. Very easy to congest and once the congestion reaches the previous roundabout it's game over. Everything stops.

I you want to see a country that appears to be extremely fond of roundabouts, you should come to the Netherlands. In the past 20 years a high proportion of crossings has been replaced by roundabouts.

We do not always have sufficient space, especially in city centers. The normal solution there is to make traffic one-way only. I do not know if they consciously try to avoid left turns, but it would seem to make sense.

I would certainly advise visitors not to take their car when visiting a Dutch city center. Using public transportation is a lot easier (and cheaper).

Here in Melbourne Australia, lots is being done to remove right turns (we drive on the left here) at the busiest intersections.

Several "P turns" [1,2] have been introduced in the most congested areas, in which you need to go straight through the intersection, then wait to do a U-turn at a designated place, then turn left into the road you wanted to turn right into (or vice versa if you're coming from the other direction).

And because we have trams (streetcars), many intersections with trams have long had "hook turns" [3], signed as "right turn from left only", in which to turn right you must first pull over to the left to clear the lanes in your direction, wait for the lights to turn green in the road you're entering, then turn right. (This is not exactly eliminating right turns but it's a much safer and less disruptive way of doing them).

It all works well when you understand it, but it confuses the hell out of visitors.

[1] https://www.youtube.com/watch?v=yIREzujqOUg

[2] https://www.youtube.com/watch?v=XPe8NtwEqeI

[3] https://www.youtube.com/watch?v=Yh92LirlCf8

Thanks for sharing. Wow, that hook turn thing is weird! I can see how it works well once you get used to it, though.

If you ride a bike and have to make a turn, it’s a similar concept!

Sounds similar to a "Michigan Left"... which I've known of since I was a kid, though I haven't seen any new ones built that I know of (though, I no longer am in Michigan...)

https://en.wikipedia.org/wiki/Michigan_left

Also common in several parts of NJ, notably driving up US1 between Phila and NYC.

New Jersey does jughandles where you do a right turn after the intersection and then a mini-cloverleaf.

Detroit/Michigan go through the intersection in the left lane, u-turn after the intersection, then turn right at the light.

Have lived substantial years in both states.

New Jersey has the driver drive through the same intersection twice.

Michigan has three intersections: the first one you drive through, the second for the u-turn and the third for the right turn, although the u-turn and right turn could often be done on a red light with low traffic, so it might be faster.

Both require more infrastructure (clover leaf lanes or the u-turn and the light for it)

Driving north on US1 between Phila and NYC, there are several turns where you turn/fork right before an intersection, and then make a left onto the minor road. Particularly true in the 20 miles on either side of Princeton.

Yes, I've seen the right-turn after the intersection too.

e.g (google maps)

https://www.google.com/maps/place/Princeton,+NJ/@40.3667281,...

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 signals, pedestrian crossings in America are rarely protected. Turners-on-red rarely come to a stop, and are usually looking to the left, meaning they don't notice a crossing pedestrian until the last minute. Same for left-turners, who are paying more attention to the opposite lane. When left-turners misjudge the speed of oncoming traffic, you can bet they'll sooner accelerate into a pedestrian in the crosswalk than allow the oncoming car to hit them.

I ran into this problem (or rather, this problem nearly ran into me) quite often in Atlanta, where many impatient drivers use neighborhood streets to leapfrog standstill highway traffic. On the bright side, the city is experimenting with scramble crossings, which feel quite a bit safer to me.

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.

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

Trains and buses are loud too.

Buses take the place of 20-40 cars. Trains take the place of hundreds of cars, are quieter than the highway they replace, and only pass by every 5-15 minutes, compared to the constant drone of highway traffic.

Yeah, and anybody who can't afford to buy a home in the city should just stop coming here. Maybe they should all have to leave by sundown too :)

They can have multiple free-of-charge parking garages on the outskirts that are associated with a light rail system.

So you park, hop on the metro, and head into the city without having to worry about the nightmare of parking or the stop-and-go traffic.

I never, ever drive into LA. I use the free parking at an outlying metro station and ride the train in (20 min). You can even leave your vehicle overnight so you can go out for drinks and crash at a friends place (even if you don't train runs until 2am). It's a night-and-day improvement on having to sit in traffic on the freeway, spend 40 minutes finding street parking, worry if someone is going to steal your catalytic converter, etc.

An added benefit is that I go into the city much more often than I otherwise would because I know that the whole process is pretty stress-free.

Why not just extend a light rail system to suburbs? It will be much faster to have point-to-point rail than car + rail.

> Why not just extend a light rail system to suburbs?

The question we should be asking is more like "why did we tear them all up"? Lots of US metro areas did have this until demographics changed in the mid-20th-century and anti-growth/anti-housing/anti-mobility mindsets took over.

You see it in eastern cities, like the Cincinatti Subway that was canceled forever in 1928: https://en.wikipedia.org/wiki/Cincinnati_Subway

Why their change in attitude? "[Cincinnati's] strategic location also provided a prime destination for migrants, who did not desire to go too far north and wanted to maintain some proximity to their southern home. Additionally, Cincinnati was not as large as some other northern cities, and thus it offered cheaper housing prices for migrants. By 1930, 34264 of Cincinnati’s African American residents were Southern-born, constituting 71.4% of the city’s Black population." https://jackdelisiohist415.wordpress.com/the-great-migration...

The Bay Area is a similar story and had several electric(!!) interurban rail systems:

- Until 1934: the Valley connected to San Jose and to the Southern Pacific main line at Mayfield (Palo Alto): https://rodsinks.com/images/1915map.png https://en.wikipedia.org/wiki/Peninsular_Railway_(California...

- Until 1941: most of Marin County connected to San Francisco via ferry from Sausalito: https://i.imgur.com/GR4Trvv.jpg https://www.mendorailhistory.org/1_railroads/nwp/interurban....

- Until 1948: Contra Costa cities connected to San Francisco via ferry and eventually the Bay Bridge: https://en.wikipedia.org/wiki/Key_System https://www.foundsf.org/index.php?title=Key_System_and_March...

- Until 1941: San Francisco connected to Oakland, Berkeley, Walnut Creek, Pittsburgh etc, then rail ferry over Suisun Bay, then on to Sacramento, Woodland, Yuba City, Oroville, and as far north as Chico! https://www.american-rails.com/images/4320087869038472230602... https://en.wikipedia.org/wiki/Sacramento_Northern_Railway

Meanwhile back in 2021 are just now electrifying the Caltrain corridor, and the same areas that shut down their original electric rail systems also successfully fought off BART in the '60s:

- This was the planned first phase of BART: https://i.imgur.com/hVT6fya.jpg

- And this was the way it was imagined to expand: https://i.imgur.com/TQ3PNL0.jpg

What changed around 1940 and made Bay Area voters hate transit and housing? Same old, same old :( https://belonging.berkeley.edu/sites/default/files/blacks_ch...

I'm an engineer from Europe. I have an idea of a light suspended rail for point-to-point transportation (personal public transportation). It should be divided into two main parts — 1) high speed, high performance network for city, and 2) low speed, low performance, but low cost and low maintenance network for suburbs. I'm not sure is my idea viable, because, IMHO, it should be already developed in the USA long time ago. :-/

For sure! Although this is a pipe dream in the real world. We should work towards solutions for today as well as advocating for fewer cars in the long-term.

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 shopping mall / restaurant / business meeting): walk further (many places to park are inaccessible) back to the car, drive a block or two more than you normally would. Extra time: +5 minutes to walk, +10 minutes for those 1-2 blocks (traffic is heavy).

Now the "best" part: Consequences if you want to drive into the city center: you need to make a sequence of correct turns 1-2 kilometers before your target, and if you don't, you are punished with extra 20 minutes in traffic at least (and still won't land where you wanted) - there is simply no route to where you wanted to go unless you pick 1 specific ideal route which many drivers don't know. Results: if you know the city / have good gps (Google Maps sometimes gets it wrong) +10 minutes in traffic, if you don't - + 20-30 minutes in traffic.

[edit] You may ask "why you can't do a triple-right-turn?" that's because the city center is not a grid. Many streets are don't have cross-paths for long stretches around historical part of the city.

Now the really painful part... Your trip outside the city center is only 5-10 minutes. Losing an EXTRA 20 minutes is a huge loss, it makes the ttrip almost as bad as walking - but inside a car. Bad for everyone really.

My main beef is with the fact that many places in the city become almost inaccessible due to a huge reduction in possible routes. E.g. 7 years ago I could get to a large mall / parking area next to the town square maybe in 5-6 diffferent ways (allowing me to balance the traffic out).

Now there's 1 way only from my side of the city, and I can't balance anything out by going where others aren't.

Guess the "grid" street network is really a hard prerequisite.

As for safety, safety records in the city haven't moved at all in the past 10 years so I don't know. (But traffic has grown so maybe it's ok?)

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 like inherently an issue in this context.

edit-add: biased in the sense that I really dislike cars and live in NYC in large part because you do not need one here

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 last decade, if you make it harder to get to the downtown area it will become a ghost town.

You could replace cars with public transport rather than just moving the cars. If you don't want to build too much infrastructure then buses and bus lanes work well.

One thing to remember about NYC's crazy tolls and congestion pricing plans is that there are not many reasons why visitors should need to drive in. There's NJTransit, PATH, light rail to Hudson valley and CT, LIRR, Amtrak, so many regional bus routes and frequent shuttles to EWR and other popular places, where most of these have park-and-ride options. And then of course once in the city there are subway and buses. Other cities that want to copy the car-discouraging policies should think about what the alternatives are.

It was cheaper and faster for me to drive 25 miles into Manhattan than take the train in from a walkable station. Then getting back out doesn't have to be at the mercy of the train schedule which is often every two hours for the line in question.

Park + ride at the outer edges of the city center. But most American cities are probably a lost cause.

Lol, have you been to the Midwest? In small and medium sized cites there downtowns are often dead, including the small city I grew up in. All of them easily accessible by car. Dead city centres in North America more have to do with the post war experiment of subsidizing inefficient sprawling car dependent suburbs. If you want to actually understand this read more from the advocacy group Strong Towns[0] they also have a great YouTube channel. Now compare small Midwest cities to small cities in the Netherlands like Leiden or Haarlem and you’ll see limiting traffic from downtowns has little to do with how well they do economically.

[0] https://www.strongtowns.org/

That’s not as true as it used to be, but I don’t disagree with the wider point.

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.

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.

Nice to see my town mentioned! I hope we remove even more of the current traffic roads in the center, it is great.

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

It certainly isn't any more, but before the 70s the Netherlands was looking at America when it came to modern infrastructure. Lots of cars, huge roads, pedestrian hostile intersections, massive amounts of and ridiculous highways (Just look at this crazy thing: https://mobile.twitter.com/notjustbikes/status/1176840020751...). It didn't kill the downtown in the Netherlands and they were in much the same position.

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

> that’s how you kill a city center.

This is a function of American cities being poorly designed. You are expected to arrive by car from the sprawling suburbs. I agree with your exceptions, NYC, Chicago: but I'd add, almost every city in Europe, such as the grandparent was talking about.

If this poor design is killed, hopefully something better can arise.

Honestly, your money is not worth the congestion, noise and air pollution it requires. It’s a real shame your locality does not provide good rail connections.

homelessness is a big issue in NYC, it doesn’t seem clear to me that cars have much to do with it, compared to, say, lack of affordable housing. perhaps we could reclaim all the parking space to build more housing

> 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.

The bussiest city centers tend to be the least car and most pedestrian friendly ones. Park the car at the border of the center, then walk into the center.

When you say "then walk into the center", you do realize you are talking about a (edit) 20-30 minute walk one-way. A car could cut that in 2 minutes.

In my lifetime I was a driver in a city where it took exactly 5 minutes door-to-door from my home to ANY location in the city (at night). During the day it was maybe 8 minutes.

Then some years went by.

I now live in a city where at night it's 20 minutes, and during the day it's 45-60 minutes.

From 5/8 minutes to 20/45-60 minutes.

It's the same city.

Things change, I get it. It just feels like things are getting worse and worse and yeah, it elicits serious questions like "is this going to be my last car, ever?" etc. :)

Don't you ever use public transportation? Most larger European cities have quite acceptable transportation. Also one of the reasons it takes longer is probably that there far more cars on the road and everybody is using their car even for short trips.

> In the vast majority of the rest of the US

The cities in these places don't generally have the problems that the GP was talking about: the streets are mostly planned and overall car-friendly, and if you miss one turn there's likely a close opportunity to correct your route.

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.

Moreover, suburbanites largely don't want to visit the city, they either do by necessity or for special occasions like a big game or a designated social event.

I see this in Seattle so much. People complain about their version of what they think my city is, swarm in for a big football game or whatever and have a great time once every few months, then swarm out to complain more about a city they’re not even in

In my town you have largely 4 options: - walk - drive - take a bus/tram - bike

Walking is too slow and cumbersome for most people (e.g. 6-8 km one way to work seems like too much to do every day), and impossible if you want to go shopping anywhere except on your way to work.

Public transport is really slow and not as flexible as you want (many places without good connections, wait times 15-20 minutes, transit times 20-50 minutes).

So you are left really with bike (flexible, constant travel time regardless of traffic, keeps you fit -- but very susceptible to bad weather) and car (flexible, fast, great for transporting items -- but very susceptible to traffic).

Biking is not that susceptible to weather imho. When it rains you can wear a rain coat and rain trousers. When it's cold you can wear any outdoor jacket (gore tex is great even if maybe not healthy). When it snows you have to work a bit harder. When there is ice you can use tires with spikes for great grip. The worst is hot weather, since you can only shed so much clothing. An ebike helps here, but that reduces the health benefits.

Cycling in the rain is only a huge problem when the infrastructure is crap. Riding in a flooded gutter, getting splashed by passing motorists and being left-hooked by people who can’t see clearly through a wet windshield is dangerous and unpleasant. Cycling on a dedicated bike path with good drainage, mud guards and a waterproof is fine, imo.

Sure if you are super motivated you can bike in any weather. But for 95% of people they will only be willing to bike if it is nice out.

The average person is not going to go out and buy a fat bike or spiked tires for the winter. And they probably shouldn't, biking in winter is dangerous if you don't know what you are doing. And sure I could wear a full rain suite and bike in the rain, but that is far less convenient than just driving and wearing a light jacket. So sure it is possible to bike in all weather, in the same way that it is possible to walk 5k, just no one wants to.

Dublin, which is crap for cycling infrastructure and weather in the winter, has about a 25% higher cycle count for summer months, according to the 2019 data (the last year unaffected by covid).

Biking in the rain is such a laughable idea to me. I wear glasses, walking in the rain is a pain in the ass as I can't see shit, it would be impossible for me to ride a bike in the rain.

That's just a first order problem for me. Drainage in a lot of city roads is pretty awful so bicyclists have a pretty good chance of getting swamped at intersections or knocked over if a bus or truck sends a wall of rain water their way.

I guess if you don't need glasses and live in the suburbs biking in the rain might not be too terrible. I couldn't imagine it in the city center of any city I've ever been to though.

It still sucks if you have to look (and smell) presentable at work. Even if you bike at a leisurely pace you and your suit will be drenched if you bike to work in a rain coat and rain trousers.

Anytime I want to spend time in DC, I definitely just drive to Greenbelt, park, and take the metro to whatever part of the city I’m trying to go to. It’s a sanity-saver over trying to find parking.

>Extra time: +5 minutes to walk

why does removing left turns make it longer to walk? Can pedestrians even make "left" turns?

It's because they have to take a different longer route to a different parking space.

A lot of times when they pull left turns it means they’re pulling out the stoplights, putting barriers of some kind down the middle and you can’t cross at that spot at all anymore on foot or in a car. If you have to park on the opposite side of the street from where you’re going you may be walking blocks just to cross.

Sure you could try jaywalking but that’s probably not a bright move in a lot of cities.

I’ll be honest I have no idea why you all are downvoting. This literally happened in a city near where I grew up and it is a giant pain. I presume he was actually asking the question because he didn’t understand why it would require more time.

Seems like an argument for more pedestrian priority crossings.

I think the downvotes are probably because none of what you write makes sense in the "old European city" the ancestor comment suggested.

Although the article is about America, so shrug

Usual car-oriented person rant about how this measure affects you personally and harms your convenience.

Complaining about traffic in the center of an “Old European town” tells me you might be doing things wrong from the get go.

I am presenting a counterpoint to the claim in the article that "it's just 1 more block" in a real world scenario (under somewhat different condition though: non-grid street network).

Do you think the phenomenon I described does not exist, or are you saying it's not relevant?

I’ve driven in places that forbid left turns and the impact is nowhere near what you say it is - your example appears very specific to your town where things seem particularly bad but also your phrasing (“punished” by traffic - guess what, if you’re driving, you are traffic) is not very objective for a rational, general counterpoint.

I think the trilemma is something like: improve traffic capacity, reduce conflict points, forgive wrong turns — pick two. The increasing popularity of GPS makes it easier to drop the last item. Of course, it's going to take some getting used to.

> if you want to drive from within the city center to the outside (e.g. go back from a shopping mall / restaurant / business meeting)

But I don't know if being able to do this is a reasonable expectation in the first place. Why do you have a car in the centre of a city? They aren't designed for cars. Live in the suburbs or countryside if you want a personal car.

> almost as bad as walking

What's bad about walking? It's good for your health, good for the economy, good for the environment.

If you are in a car, chances are the goal was to get there more quickly than you could by walking. If you are getting there more slowly by taking a car then it was "worse than walking" by this metric. No one is criticizing walking as a general means of transportation.

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.

> Would the city economy suffer? Maybe. Would it be a more pleasant place to live and work? I think so.

The results of some European cities doing basically this suggest that the city economy likely wouldn't really suffer (and in fact could improve in many cases).

That said you don't need to completely eliminate cars; blocking through traffic and severely restricting car parking can have much the same effect. If you can take a direct route on foot/by bike but have to take a more circuitous route by car, more people will do the former.

See also "Why UPS drivers don't turn left and you probably shouldn't either" at https://news.ycombinator.com/item?id=25379743

That definitely doesn’t apply. UPS drivers have routes with multiple stops. Planning routes to avoid left turns is a very different (much more feasible, convenient, and efficient) than going from A to B without left turns.

Or just remove cars from the city altogether.

James Dean died in an accident caused by just that: "Intersections are dangerous because they are where cars, often moving very fast and in different directions, must cross paths."

"As Turnupseed's Ford crossed over the center line..." https://en.wikipedia.org/wiki/Death_of_James_Dean

Redacted photo (save, only the street is shown), that shows the intersected lines: https://www.alamy.com/stock-photo-scene-of-james-dean-crash-...

Google maps, and other similar routing apps, should offer a no left turn option!

Heck, I'd be thrilled by a "avoid intersections where the bottom 20% of drivers get stuck waiting for several minutes trying to make the turn" option.

99% of the time I wouldn't use it. But the 1% of the time that I'm doing something stupid the last thing I need is a extraneous hard intersections.

It's not like Google doesn't have the location data to figure out the difference between intersections where traffic is slow and steady vs where people routinely get stuck.

I use the “alternate route” hints for this - if the left turn looks dicey (not protected, busy) I’ll keep going and let it reroute. Usually finds a stop light.

And while we're at it, in the UK at least they should have an option for not sending you down bidirectional single track roads.

No, that 35 mile drive down twisty single track country lane with occasional passing spots will not save any time over the 40 mile motorway. Even if the road is _technically_ 60mph, you'll never reach that speed unless you're on a motorbike...

There's this awful route Google Maps will give you, through the twisty back roads of SF because it thinks it can get you to the 101 faster. But it's sending everyone that way, so there's huge traffic on these narrow neighborhood roads. It's not a shortcut if everyone knows about it.

I think map apps should be optimizing for something more complex, like least amount of directions within a five minute arrival window. Saving two minutes of driving time isn't worth having to make eight more turns.

Agreed - a "least hassle" route would be better.

Google maps has sent me on some really werid routes with endless turns left, right right left right right right left left right left etc etc vs just staying on a main road with only one or two turns for only an extra couple of minutes minutes more

I'd be more than happy to stay on the easy main roads and turn once or twice rather than hack through the backstreets just to save <5% distance/time

I've found Apple Maps better for that.

Before I switched, I found Google maps really liked to have you turn left one street early, then turn right then turn left. I guess it was trying to eliminate the delay from the left turn at the busier intersection. It was pretty much always worse.

> I think map apps should be optimizing for something more complex, like least amount of directions within a five minute arrival window. Saving two minutes of driving time isn't worth having to make eight more turns.

One issue is, as you say, that shortest-path routing can overload individual roads. There is an interesting and related concept in theoretical CS: oblivious routing. Instead of solving “What is the shortest route to my target?” locally, you try to determine a selection of routes that, if followed by every participant, minimise congestion (the maximum amount of vehicles over any road, relative to its capacity). Surprisingly, it is always possible to determine such routes, even if they are not allowed to depend on traffic conditions (how many vehicles try to go from A to B, how many from C to D, etc) ― this is what the “oblivious” refers to.

Of course, that does not solve the problem of route complexity.

Oh I hate this so much. Driving in any rural area like Dorset it’ll suggest lanes you’d struggle to fit 2 bicycles abreast. They offer a ‘no motorways’ option but I’d love a ‘minimum double track’ or whatever.

Better yet, replace intersections with roundabouts. But that would mean knocking down a lot of buildings.

Roundabouts are fantastic for the low to mid traffic density case. When you get into proper city traffic density it can start to become very problematic, particularly if you don't have a good solution for pedestrians or cyclists to bypass each roundabout crossing. Even with that roundabouts tend to get a bit chaotic once they reach the point of "is expected to have a constant stream of cars in it for the next 2 hours" which can get particularly troublesome if the traffic in each direction is unbalanced and you get people awkwardly changing up yielding rules to let the one person going east-west in or that person tries to floor it to make it in an iffy gap. Also if you're relying on them as the only means of left turn (via u-turn) the wait times can significantly increase on busy roundabouts.

That being said I absolutely love roundabouts in low/mid density areas. They finally converted the street I live on from 4 "pack cars into wait groups" stoplights and 1 "the highway just turned into an avenue and this is the first extended stoplight for that" into "never stop heaven" whether you want to just continue through or hop on the highway by putting a bunch of roundabouts and a dogbone underpass in and removing left turns for most of the avenue.

For proper city areas I'm almost certain better results would be achieved by using the space for any form of mass transit instead of more road. That and I shudder to think of roundabout traffic in a bumper to bumper scenario when one of the arteries out of the city gets blocked for 10 minutes (or months of construction).

Roundabouts have better throughput in most cases, but have higher variance for time to complete transit, as one strong stream of cars from a single direction can choke off the alternative directions.

The photos in the article are irrelevant to both subject of the title - city streets, and turning left away from controlled intersections: The intersections are large, arterial-scale, rather than typical surface streets in a city. Both have medians to prevent left turns away from the signalled intersections.

The first photo also provides an example of a left turn lane blocked by a t-bone crash of two drivers who appear to have not been turning at the time of their crash. That's one way to stop drivers from turning left, but perhaps not the best possible traffic control strategy.

Side note - Based on a quick search of the article's tagline, this article was simultaneously broadcast across many outlets on June 2nd, 2021 [0]. Someone had a motivation to get this distributed far and wide.

[0] https://duckduckgo.com/?q=%22sick+of+dangerous+city+traffic%...

Nothing evil about the motivation: this article is from The Conversation (my employer) and we distribute all of our articles widely under a Creative Commons license: https://theconversation.com/us/republishing-guidelines

Our motivation is to publish articles by experts sharing their knowledge and spark discussion, as has been done here on Hacker News: https://theconversation.com/us/who-we-are

There's a lot of really idiotic left turns across multiple lanes of traffic which are allowed outside of traffic light controlled intersections. Those lead directly to the "wave of death" situation where people (if they've been explicitly given such a wave or not) tend to try to bolt across traffic that they can't see coming.

A traffic safety solution would be to just eliminate those left turns and run the lane divider bumps down the middle of those roads. Businesses would probably scream quite a bit since left turns into their parking lots would no longer be possible, but you'd cut out a ton of accidents. Suicide lanes turning across multiple lane would also similarly need to be removed.

There are a ton of drivers who try to push through deeply stupid left turns in the middle of heavy traffic, because they're technically legal. Even making them do a U-turn at the next light would be safer (or yes, roundabouts, please).

If you found this interesting, I highly recommend the book Street Fight by Janette Sadik-Khan. She was the Commissioner of the NYDOT, and she was able to make really meaningful improvements by looking at relatively easy, low-cost solutions that didn't require enormous political capital. Things like expanding the sidewalk at corners out into the lane where cars are parked, which reduces the length of crosswalks and lowers pedestrian injuries. It's not just an interesting book about transportation infrastructure, it also really has some great lessons for startups about finding ways to make change in large, hairy systems where many of the participants don't want change.

The Michigan Left is such a great concept. Instead of turning left, you turn right and every boulevard has tons of dedicated u-turn lanes. So to go right, you turn right easy peasy. To go left, you also go right and then make your way to the left lane where you will be able to turn around and go your desired direction. There are so many of them that if you miss the one you want, there will be another a hundred feet down the road. It’s great.

https://en.m.wikipedia.org/wiki/Michigan_left

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 visible at all times, instead of in a blind spot.

https://bicycledutch.wordpress.com/2018/02/20/a-common-urban...

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.

This looks good. Although I do not see how this can be done without tearing down 10% of a city.

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.

Those are almost certainly people making what I call "right hand turns from not the rightmost lanes", which is, IMO, the single most dangerous traffic violation a biker can encounter. It happens often, it's hard to avoid, and the consequences are bad¹.

My jurisdiction (and most I have encountered) require a right-turning vehicle to merge first into the bike lane, if there is a bike lane to the right. (And no further car lanes. Some intersections will shunt right turning vehicles across the bike lane, first, into a turning lane, and then turn at the intersection.)

My "closest call" was here: [1] I was going southbound through that intersection on a fresh green when a vehicle right turned from the left turning lane (i.e. he was also initially headed south bound). Absolutely crazy maneuver. I was forced into the right there (because otherwise, we were going to collide) and was just barely able to make it — I could feel the traction in my back tire was just barely holding onto the road the whole way through, since I was also braking like hell. Driver was just like "uh, oops?"

I'll usually watch the lane just left to me for drivers whose movement indicates some inclination of thinking about right turning (again, from the wrong lane). I don't know if people worry about blocking bikers or what. Like, if you're in my lane to make a right, and you're signalling that, I prefer that, because you're not going to pop into my lane & try to kill me. I'll wait behind you while you make the right. (Or merge around you on the left, if I can safely do so.) Or at the very least… if you're going to make an illegal right, please, signal.

[1]: https://goo.gl/maps/U2smgkRmagmcwsBAA

¹way worse than things that sound worse: car driving the wrong way — which itself happens way more often than it really should — it's much "better": I can see it coming. Honestly, as a cyclist I feel like I'm the only person out there who took a course on how to drive a car.

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.

when I lived on California i was amazed at how many pedestrian deaths there were in San Francisco, a city mired with no left turn rules. they allowed right on red, which I think contributed. I think most traffic engineers know about the green wave and improving traffic flow, but the political mission is to slow traffic to save lives and encourage mass transit. it's a shame

If you're reading this from Australia or any other country that drives on the left, removing right turns has the same effect.

This article is so auto-centric, the author only considers the safety of people inside cars. Banning left turns in cities is a GREAT idea! The group of people most threatened by left turning cars are people walking. Control F for "pedestrian" or "walk" in this article. Nothing. American traffic engineering is so car-dominant, they fail to consider the most vulnerable road users. Pedestrian fatalities in the USA are at 30 year highs. Design for the healthy human living habitat we desperately need. Good human habitat requires safe walking infrastructure for humans of all ages, sizes & abilities.

Yes banning left turns will definitely stop drivers from illegal left turns /s

Existing on only 2 dimensions has made my life much simpler and safer.

And right turns for those driving on the wrong side of the road. ;-)

Trains.

Actually the safest way to make cities less dangerous is to just ban people from going outside.

Tldr: roads with 5+ lanes should be one way.

Sick of dangerous city traffic? Leave

Probably one on the most American articles I've read in a while... "Great job team"...

Also, I wonder the impact of introducing proper diving tests and learning to drive.

Once again, a clear warning that an article is US-specific would be nice.

Agreed. Advice to "avoid left turns " is not directly applicable to "drive on the left" countries.

It does closely enough, here it would just translate to ‘avoid right turns’ or ‘avoid turns across opposing traffic’.

Did you see the word "directly" in the above sentence?

yes, it's interpretable after reading the article. It's not a simple or accurate headline, though. As per grandparent comment, " a clear warning that an article is US-specific would be nice."

In many countries such turns are either not dangerous or avoided using roundabouts.

Stroads exist almost only in US.

https://www.strongtowns.org/journal/2018/3/1/whats-a-stroad-...

Design plays and engineering play a massive role in the safety of streets. Q: People make mistakes regardless of training. How do you dolve those problems? A: You work to understand them and then eliminate them with intentional action.

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