[HN Gopher] Should traffic lights be abolished? (2021)
___________________________________________________________________
Should traffic lights be abolished? (2021)
Author : wslh
Score : 35 points
Date : 2022-09-15 13:15 UTC (9 hours ago)
(HTM) web link (freakonomics.com)
(TXT) w3m dump (freakonomics.com)
| smm11 wrote:
| I'm in Southern California, and traffic lights are already
| ignored. (YT - Fiery, fatal Windsor Hills crash)
| incomingpain wrote:
| I wish freakonomics had an rss feed.
|
| The thing that's happening right now is that many large cities
| have more or less enabled the possibility of carless transport.
| Cycling is now completely viable and even better, costco has a
| foldable ebike for like $400. Weather sucks? Work from home
| instead. Gotta go? Taxis and buses exist. What do you pay in car
| insurance? $1000/year? How many trips in the bus is that? Many!
| You also dont pay for parking anymore. Cycling is great exercise
| burning fat instead of money. It's a huge net benefit to society
| which is 70% overweight. National wealth will certainly increase.
|
| Which brings me to traffic lights. Cyclists already don't obey
| them. Why don't we just abolish them? Traffic lights function
| just fine when they go out or blink red.
|
| If stop signs replacing all traffic lights is an inconvenience
| for cars... might I recommend a bike?
| [deleted]
| alexb_ wrote:
| Why do anti-car people not seem to understand that people don't
| want to ride a bike everywhere? You can't just tell someone to
| completely change their lifestyle to avoid potential problems,
| and then act like they are the insane ones for not wanting to
| listen. I want a car. I like my car. Demanding that people give
| up their ability to get in a car and drive somewhere so that
| all of America's infrastructure can be changed is insanity.
|
| >The thing that's happening right now is that many large cities
| have more or less enabled the possibility of carless transport.
|
| I actually like to _leave_ the cities I live in sometimes. Or
| maybe I don 't live in a city, and I want to visit it with _my
| car_.
| seszett wrote:
| Looks like I answered the wrong comment earlier:
|
| > _I actually like to leave the cities I live in sometimes._
|
| You can own a car and still use a bike when staying within
| the city. That's what most people do here.
|
| > _Or maybe I don 't live in a city, and I want to visit it
| with my car._
|
| That usually leads to a worse experience than taking public
| transit or a shared bike, and I don't think this use case
| should be supported.
| Eavolution wrote:
| What about people who live in the country who don't
| actually have public transport options?
| dont__panic wrote:
| The issue is that cars _do not scale well_. It 's like
| running a tech company where IT manually triages every single
| ticket, with no self-service system: after a certain point,
| you just can't scale it up. Think of public transit, walking,
| cycling, scooters, etc. as the real-world transportation
| equivalent of automation. Cars take up a massive amount of
| space for a single person and dump tons of CO2, pollutants,
| and noise into their surroundings. And they routinely kill
| and/or maim people.
|
| It's fine to own a car, park it in your garage space in a
| city, and use it to drive out of the city from time to time.
| It isn't OK for cars to dominate 50% of the space in modern
| American cities for roads, free street parking, and parking
| lots. Particularly because it comes at the expense of space
| that could be used for more scalable transportation
| solutions.
|
| > Or maybe I don't live in a city, and I want to visit it
| with my car.
|
| Sure, feel free to drive to the other city by car. But in a
| more scalable world without hellish traffic, you'll have to
| get around on foot, by bike/scooter, or using public transit
| in the city. Because cars aren't scalable.
| Schroedingersat wrote:
| > It isn't OK for cars to dominate 50% of the space in
| modern American cities for roads, free street parking, and
| parking lots. Particularly because it comes at the expense
| of space that could be used for more scalable
| transportation solutions.
|
| 50% sounds extremely generous. There are 8 parking spots
| per car and one car per person which is around 350m^2 of
| area per person (some portion of which is stacked).
|
| This is one median lot per household on parking alone.
| shlurpy wrote:
| Empirically, most people care more about making the trip
| efficiently then how exactly it's done. If all those people
| are motivated to not use cars, think of how much less traffic
| there will be for everyone else? It turns out that bike and
| pedestrian friendly cities are also some of the most car
| friendly ones for this reason.
|
| https://m.youtube.com/watch?v=d8RRE2rDw4k
| at_a_remove wrote:
| I'm handicapped.
|
| The bike vision of the future features all of these tanned,
| lean people cycling everywhere (and even making turn signals
| with their hands, which happens so infrequently IRL that I
| generally note it at once a year), and I guess everyone else
| just hopes they don't get stabbed if they ride our quasi-
| subway.
| incomingpain wrote:
| >Why do anti-car people not seem to understand that people
| don't want to ride a bike everywhere?
|
| To be upfront, I'm a car guy. My last car had >700hp,
| currently a hot hatch. Soon I have to go dadmobile, vw camper
| id buzz... oh do tell me more.
|
| My bike? I bought one of those huge/wide bike seats. My bike
| seat is worth more than my bike lol. I find it crazy there
| are people with ultra light carbon fiber sport bicycles about
| to be stolen any moment. Nobody stealing my piece of shit
| bike.
|
| >You can't just tell someone to completely change their
| lifestyle to avoid potential problems, and then act like they
| are the insane ones for not wanting to listen.
|
| Because of the boon on cycling. We suddenly have big lobbying
| and activism toward promoting cycling.
|
| The thing is, don't just write off this factor. There's lots
| of good benefits to society if we all move to bikes and
| shared infrastructure to rental vehicles or transportation
| services.
|
| >I want a car. I like my car. Demanding that people give up
| their ability to get in a car and drive somewhere so that all
| of America's infrastructure can be changed is insanity.
|
| I don't think anyone is going to that extent to say you can't
| drive anymore.
|
| >I actually like to leave the cities I live in sometimes. Or
| maybe I don't live in a city, and I want to visit it with my
| car.
|
| Nobody is saying you cant drive. No politician will survive
| assassination if they banned cars.
|
| There are ebikes with >100km electric range that can go
| 35km/h. Going to be hard to tell me that setup won't do what
| you want it to do.
| nebukhadnezzar wrote:
| Because anti-car people understand that it is absurd to
| (mainly in cities) sacrifice so much space, environment, and
| health to accommodate car people's laziness. People living in
| the city have to sacrifice clean air to support the suburban
| car commutes. This is absurd. Many car-minded people are
| simply to lazy to take alternative modes of transportation,
| even if they exist and are really well implemented (as they
| are in most European cities).
|
| The Netherlands does this properly. But as a European having
| traveled to the USA it is mind boggling how car centric
| cities are. With all the inefficient and extremely costing
| infrastructure investments car centric cities require.
|
| A solution for people like you would be to park your car near
| the city borders and take public transport. But I don't know
| a single car owner who isn't too lazy to just drive straight
| into the city.
|
| Having designed our cities around the car will be really
| frowned upon in the future. It's crazy how much people who
| use alternative modes of transportation sacrifice (in tax and
| health) to support this.
| davchana wrote:
| I live in central valley, California. When I want to visit
| downtown san Francisco, or SFO Airport, 99% of the times I
| park at first Bart Station, and use Bart from there. The
| only time I go not is if I am picking a couple of family
| with lots of luggage.
|
| So, now you know a car driver who drives about 16k miles a
| year, and also is not lazy enough to park at city borders &
| use public transport. & Bart Parking is almost always 60+%
| full.
| jeffbee wrote:
| The ability of exurban dwellers to visit a city with their
| car is of no interest to the people in that city. Why should
| they care?
| ghaff wrote:
| Are you sure? A city that's unwelcome to commuting workers,
| local visitors coming in for entertainment, shopping,
| dinners etc. may not be a city that the city dwellers want.
| Of course they're welcome to discourage visitors however
| they want.
| jeffbee wrote:
| Virtually every city in America destroyed itself in the
| pursuit of what you suggest: everyone will live out in
| Whiteville and they'll just drive downtown for culture,
| commerce, and employment. It didn't work. The freeways
| and parking lots cost too much, and the commuters don't
| pay enough taxes to balance it out.
| ghaff wrote:
| And many don't mostly need to come downtown for commerce
| or employment any longer. And culture can be a handful of
| times a year. That's my situation. I rarely come into the
| nearest major city any longer. It's not that I _don 't_
| come in but I'm very selective.
| jeffbee wrote:
| Well it sounds like we agree then. There's no reason for
| a city to hollow out its neighborhoods to make space for
| the cars of people who drive into town once a year.
| ryukafalz wrote:
| My city has throngs of people coming in via transit
| whenever there's a major sporting event or concert. I
| know, I've shared trains with them many times. You don't
| have to get there by car.
| ghaff wrote:
| In my experience most are coming from nearby suburbs, not
| exurbs. While I might take the commuter rail in for a
| major sporting event or concert even if it might mean
| waiting around--or park at an outlying transit lot--It's
| pretty impractical for most evening events and this is a
| major city with pretty good transportation options
| generally.
|
| City residents can do whatever they want but I for one
| will simply not come in in general if it's too big a
| hassle. And that's fine. I have plenty of other things to
| do.
| weberer wrote:
| The NPR page lists a RSS feed
|
| https://www.npr.org/podcasts/452538045/freakonomics-radio
|
| https://feeds.simplecast.com/Y8lFbOT4
| PaulHoule wrote:
| Walt Disney thought so.
|
| When traffic is light, traffic lights make you wait a long time
| for no reason. When traffic is heavy they add insult to injury by
| taking 2 or 3 cycles to clear out the stack of traffic you're
| waiting in -- and that's just the immediate intersection,
| frequently traffic stacks up to the point that traffic flow is
| impaired in preceding intersections. That's how traffic lights
| turn a 5 minute drive into a 50 minute drive.
| stop50 wrote:
| Only if you have idiots for traffic planning. By now you can
| have sensors that detects vehycles on lanes and change it
| depending on the situation. only two lanes are in use:
| permanent green until a car on the other lanes come.
| bell-cot wrote:
| I regularly have to drive in Ann Arbor, MI - by one account
| the #1 most educated major-ish city in America ( https://www.
| freep.com/story/news/local/michigan/2017/07/25/a... ).
|
| We are _definitely_ stuck with idiots for local traffic
| planning. And those clever sensors - there is a huge
| difference between (A) a traffic light checking that Feature
| Box in PowerPoint (or Flash, or Microsoft Bob, or whatever
| software the local traffic planners use), and (B) traffic
| sensor technology being usefully implemented at the light 's
| real-world location.
| Someone wrote:
| Permanent red on all lanes until traffic arrives may be
| better. It allows you to safely switch to green faster on
| whatever lane traffic arrives from.
| bell-cot wrote:
| I've see a _lot_ of sensor failure modes which that
| algorithm would handle poorly - complete failure, failure
| to notice small /light vehicles (especially motorcycles /
| scooters / bikes), mis-reading which lane a vehicle is in,
| ...
|
| I've also seen fancy sensor-equipped traffic lights where
| the traffic flow was _improved_ by a power outage turning
| the intersection into a (legal default) 4-way stop. Major
| intersections. During rush hour.
| Someone wrote:
| > I've also seen fancy sensor-equipped traffic lights
| where the traffic flow was improved by a power outage
| turning the intersection into a (legal default) 4-way
| stop. Major intersections. During rush hour.
|
| That fits one of the main points made in this article:
| traffic lights slow down traffic. Another one is that
| decreasing speed on intersections increases safety.
|
| The magic of roundabouts is that they accomplish the
| latter without needing the former.
| EricMausler wrote:
| There is one of these on a backroad near me. I wish the
| sensor were farther away from the intersection so I
| wouldn't have to come to a complete stop just as it turns
| green.
|
| The general traffic is probably 95% favored to the
| direction I am going, and I really wish they would just
| leave it green until the other direction actually needs it.
|
| Maybe they have it this way on purpose to indirectly
| prevent speeding? I wonder if that's a consideration for
| traffic light logic or not
| MichaelCollins wrote:
| When traffic is light (e.g. at night), the traffic light
| can be scheduled to blink red in all directions. Then it is
| treated like a simple stop-sign intersection.
| bombcar wrote:
| Some around here blink yellow on the main road and red on
| the side street at night.
|
| Works decently well.
| TotempaaltJ wrote:
| Here's a good video on why (and where) none of these things
| have to be true: https://www.youtube.com/watch?v=7KPGVP85WpU
| giantg2 wrote:
| In my area people complain about needing new lights all the time.
| They theorize that there would be fewer accidents if they put in
| a light at certain intersections. The real problem are the
| drivers. Almost all the accidents I see at those intersections
| are from people being impatient and making bad choices. Those
| same people are going to do the same stuff by trying to beat the
| light or make a right on red and screw up. We can try to make the
| road design better, bit the biggest benefit would be to address
| where the ultimate responsibility for safety lies - with the
| driver.
|
| Yet the people will complain and get their new light, and we'll
| impose largely arbitrary restrictions on new drivers while
| letting the chronic crash causers slide and the people who would
| objectively fail better testing drive.
| autoexec wrote:
| In what ways do we let "chronic crash causers slide"? What
| changes would meaningfully alter their behavior? I'd argue that
| most bad drivers know what they're supposed to do, and can be
| on their best behavior during a driving test, but don't care
| about anyone other than themselves. As soon as they can they'll
| start cutting people off, dangerously passing, running red
| lights, etc.
|
| In the US, the penalties for crashing your car at this point is
| often being forced to buy a new car since even low speed
| accidents can total your vehicle, then you also have your
| insurance rates skyrocket, and you're often on the hook for a
| lawyer and showing up to court where you can face being
| responsible for hundreds of thousands in medical expenses. It's
| a pretty damn punishing system for people who cause accidents.
| I suspect that most people (alcoholics aside) are not going
| around getting into one car crash after another after another.
| It's just vast numbers of assholes each of which thinks it
| won't happen to them until it does.
| stazz1 wrote:
| The goal should be to eliminate waiting
| asah wrote:
| lol, roundabouts in Tokyo or Manhattan... imagine... a skyscraper
| in the middle... underground entrances to it... mechanicals on
| the ground floor because nobody wants to have cars coming
| straight at them...
| noobermin wrote:
| I think only the netherlands does it better but in the US
| roundabouts are generally worse for pedestrians to cross.
| bombcar wrote:
| The problem for pedestrians is the flow of traffic never
| naturally stops, so you are either waiting forever or dodging
| cars.
|
| However, you may only have to cross one lane at a time which
| may be a bit better.
| jimmygrapes wrote:
| Pedestrians shouldn't be anywhere near roadways imo, but that's
| a whole other discussion
| KIFulgore wrote:
| I live near Carmel, Indiana, the roundabout capital of the US.
| Small ones, large ones, figure 8's, figure... double-peanut-
| looking things with elevated crossovers near interstate
| junctions. They work well and keep traffic moving.
|
| But there is a learning curve. Every new roundabout causes a
| significant jump in crashes for a short time. Though, those
| crashes tend to be "glancing blows" that cause less serious
| injuries due to the angle of attack imposes by the roundabout.
|
| Smaller cities and towns in Indiana are adopting more roundabouts
| near congested areas. It's important to introduce them gradually
| and give drivers time to acclimate.
|
| https://www.nytimes.com/2021/11/20/climate/roundabouts-clima...
| cogman10 wrote:
| A failing activity I've seen with roundabouts is when there is
| no physical barrier but instead just a bump in the road that
| everyone is supposed to go around. In those cases, a LOT of
| people end up treating the round about like a 4 way
| intersection with the worst of all world (because you don't
| know if someone is going to go against the roundabout rules to
| turn left).
|
| There HAS to be a lump big enough to cause someone to go the
| right way around.
| fudged71 wrote:
| What if they put a flexible bollard in the center?
| consp wrote:
| All anecdotal but hey: The roundabouts I've seen fail (we
| have many) are those with not enough and too much
| obstruction. The versions with some form of gradual grace
| (curved edges around a center platform or lots of grass and
| a bump) tend to work best. One of the worst ones was a very
| large one with a meter high round wall as center barrier
| which caused lots of damage to those who made a mistake.
| The too small ones are just intersections with minor
| obstacles to navigate.
| giantg2 wrote:
| Tall stuff impedes vision. The gental slope around tends
| to be accommodating for tractor trailers. Short stuff,
| even just a regular curb inside of the sloped area should
| be enough to stop cars from driving through it. Some
| short flowers or plants can help draw attention.
| lcnPylGDnU4H9OF wrote:
| Kinda off topic, but this reminds me of a racing game I
| played which had a track that featured a roundabout with a
| bump just perfect for Dukes of Hazarding it.
|
| So ideally the roundabout also doesn't encourage sweet jumps.
| (Unless there's a very well-designed designated landing spot
| that prevents damage to the vehicle. Probably tax dollars can
| be spent on better things.)
| yamtaddle wrote:
| Ours typically have a bit in the middle that's usually grass
| behind a curb, then a _lower_ raised bit with a bevelled curb
| that 's all concrete surrounding that, or else just an area
| around the center-grassy-bit that's even with the rest of the
| pavement but marked off with "don't drive here" stripes. The
| ordinary lanes are outside both.
|
| I assume those are affordances so buses (say, school buses),
| trucks towing trailers, and stuff like that, can actually
| _use_ the roundabouts. They 'd be damn tricky for them to
| navigate, otherwise.
| bretthoerner wrote:
| Recent video where roundabouts in Carmel are a big focus, from
| pedestrian/cyclist POV:
| https://www.youtube.com/watch?v=rqx6aRCO0MI
| formerkrogemp wrote:
| > I live near Carmel, Indiana, the roundabout capital of the
| US. Small ones, large ones, figure 8's, figure... double-
| peanut-looking things with elevated crossovers near interstate
| junctions. They work well and keep traffic moving. But there is
| a learning curve. Every new roundabout causes a significant
| jump in crashes for a short time. Though, those crashes tend to
| be "glancing blows" that cause less serious injuries due to the
| angle of attack imposes by the roundabout.
|
| I have a reason to visit Indiana now! Cool. I wonder how I can
| sell the family on a trip to Carmel or similar city :).
|
| The town I grew up started adopting roundabouts as I started
| driving. They're awesome and so much faster than red lights!
| They annoy my older relatives and coworkers as well.
| smeej wrote:
| Carmel is basically a suburb of Indianapolis, and all kinds
| of things happen at the Indianapolis Convention Center.
| Surely you can sell your family on one of them!
| mobilene wrote:
| I'm near Carmel too. I remember when the roundabouts started
| going in. They replaced four-way stops that backed up for miles
| at rush hour. The roundabouts made traffic flow SO much better.
|
| Now Carmel is replacing some stoplights with roundabouts. This
| man's opinion is that they are not always better. But so far,
| they've never been worse.
| kevin_thibedeau wrote:
| They absolutely suck when a train of cars forms and you can't
| enter the loop. Those are the dumbest roundabouts in the
| country. They don't adequately force cars to slow down enough
| to let gaps develop in the flow.
| lesuorac wrote:
| I'm not sure that slowing the cars down would help more.
| Its much easier to drive literally right behind a car at a
| slower speed than a higher speed.
|
| Afaik, the general trend is to put a stoplight going into
| the roundabout for the few directions that cause a problem
| so that the "side streets" get a chance to go.
| smeej wrote:
| The other stupid thing about Carmel roundabouts is where they
| put them at every 3rd road crossing when it would have worked
| absolutely fine just to have the traffic going one way stop,
| because it's a neighborhood with thoroughfares and cross
| streets, and there is NEVER traffic on the cross streets.
|
| It just makes the thoroughfares slower for no clear reason.
| Maursault wrote:
| By now designing and mass producing the smart traffic light
| should be possible for not too much extra beyond the cost of the
| dumb traffic light. A smart traffic light system could
| effectively eliminate most traffic. A traffic light that is aware
| of oncoming traffic or the absence of it will remove the annoying
| instances of being stopped at a traffic light when there is no
| cross traffic, or of remaining on a timed green waiting for
| traffic that isn't there. Some cars nearly drive themselves now.
| Everything has a computer in it, why not traffic lights and
| intersections? Why hasn't traffic light technology advanced
| beyond timers and switches in the road? They need to have eyes
| and decent logic built into them. Imagine the fuel/cost/carbon
| savings alone if we had these things widely installed 20 years
| ago.
| throwaway894345 wrote:
| Simple things fail less often, require less maintenance, and
| are less likely to be hacked. I'm not saying these concerns are
| the most important, but they deserve consideration.
| fl0wenol wrote:
| These exist in many different generations (sensor-based traffic
| control devices) but as there are state and/or local
| certifications each solution and implementation must meet to be
| deployed, plus the additional cost of installing and
| periodically calibrating sensors, they are not warranted unless
| the situation calls for it. The inconvenience of waiting an
| extra minute at a minor cross-street doesn't usually cut it.
|
| If you live where there is a light that causes disruption or
| accidents because it needs sensors based on the traffic flows
| nearby, you should bring it to the attention of your local
| government. At the very least you could get them to do a study
| on it.
| Arubis wrote:
| If you'd like to simulate traffic light abolishment with no
| replacement, visit beautiful Denver, Colorado, where the sun is
| strong, the beer is cold, and the red lights are purely
| decorative.
| giantg2 wrote:
| "and the red lights are purely decorative."
|
| Philly has been notorious for this regarding stop signs.
| randcraw wrote:
| And the first few seconds of red lights.
| mellavora wrote:
| Isn't Amsterdam also famous for its decorative red lights?
| throwaway894345 wrote:
| * Laughs in Chicago *
| anotherevan wrote:
| I live in Victoria, Australia, and we've had roundabouts for
| ages. I think they are very good for a certain scale of
| road/traffic. Mostly intersections with moderate amounts of
| traffic on average, and not high-speed. e.g., the main
| intersections within housing estates. Having too many of them
| instead of give-way signs drive you a little batty (I'm looking
| at you, Warrnambool) while really heavy traffic, major
| intersections work better with traffic lights.
|
| When teaching my kids to drive, they found roundabouts one of the
| trickier intersections to navigate. You have to read the traffic
| flow. This person about to enter on your right is going straight
| ahead, so will block you entering the roundabout[1], but they
| have to wait for that person coming the other way from you and
| going straight through, so you can slip in the gap that creates
| without cutting anyone else off. As with many things it is
| familiarity and practice that makes them work[2]. I think
| roundabouts work very well here for the most part. It's not
| rocket science[3].
|
| The science of roads and traffic I imagine is a surprisingly
| nuanced expertise involving a lot of physics and psychology. I
| find when I cross over the border to New South Wales I feel like
| a long-tailed cat in a room full of rocking chairs. I eventually
| figured out it was because the signage was a different distance
| before the intersection compared to my home state. Once I was
| aware I could adapt.
|
| [1] We drive on the left side of the road because Australia is in
| the southern hemisphere.
|
| [2] I bet the first traffic lights caused an uproar. "Why the
| hell should I stop just because there's a red light?!"
|
| [3] Oh wait, actually, it is rocket science.
| ztetranz wrote:
| I'm from New Zealand where we have lots of roundabouts. My
| observation is that they work well, even with heavy traffic
| except some unbalanced conditions that can happen at rush hours.
|
| Imagine this. Driving on the right. Roundabout with four exits.
| North, East, South, West. Heavy streams of traffic entering from
| north and west. Most traffic exits at east therefore nothing to
| slow north enterers. West enterers hopefully get the breaks in
| north entering traffic. Trying to enter from south is really
| difficult because north and west enterers keep it full.
| angus-g wrote:
| I have seen a few roundabouts with metering traffic lights that
| are only enabled during peak traffic times to occasionally
| allow the "blocked" directions in. It seems to be a reasonable
| compromise.
| palmetieri2000 wrote:
| Kia Ora,
|
| Im from a chunk of Australia known for a tonne of roundabouts
| and observed the same issue. My theory is that this is actually
| roundabouts working as intended, despite the frustration of the
| South-Enterers.
|
| Basically, if the flow of traffic is both moving too fast and
| with too great a vehicle density to allow for safe entry (even
| if slow, like 1 SouthBound Vehicle for 5x Northbound + 5x
| Westbound) then the traffic organism is actually distributing
| resources based on need, rather than convenience. The flow WILL
| automatically correct itself as the population of vehicles
| diminishes, the question is if the WAIT time for Southbounders
| (and the population of Southbounders) is sufficiently large
| that interfering with their flow is actually delaying more
| people than the North and West routes, but that is more of an
| issue of roundabout placement than it is the roundabout itself
| being inefficient.
|
| (^^The above is all 100% observation and guesswork, anyone with
| some education on the matter want to chime in?)
| jimmygrapes wrote:
| It's a good load balancer for sure, but that doesn't help the
| poor sod who is in the minority who has to wait for ages
| simply for not needing to go the same direction as the
| majority.
| downvotetruth wrote:
| This is absurd.
| falcolas wrote:
| I mean, if you want all your roundabouts to be demolished by semi
| trucks and other construction vehicles. And the price for the
| transportation of goods increased due to increased damage to
| trailers and the semi trucks themselves.
|
| Personally, I love roundabouts. They're fun to drive around. But
| I have seen (and there's lots of reports about) semi tucks
| crawling over them at 5mph or less because they're all built too
| small to support a semi with a 50' trailer.
|
| My vote is, once we eliminate the need for Semi trucks for
| deliveries in the city, sure. Roundabouts everywhere. But until
| then, let's keep infrastructure sane for all the users of it.
| bilsbie wrote:
| I suppose you could make the inner part something safe and non
| destructive to drive on but still uncomfortable so trucks could
| still make it through. Maybe Make rumble strips? Still have a
| structure in the very middle to prevent head on crashes though.
| samcat116 wrote:
| Most roundabouts have a very short skirt around the middle
| island thats like 10 feet wide just for this reason. Theres a
| curb so normal cars don't go on it, but it allows wide trailers
| to cut over them just fine.
| bombcar wrote:
| Even those get destroyed in pretty short order. All the
| smaller ones around here have chewed up kerbs
| falcolas wrote:
| They do indeed. And those still damage trailers and require
| semis to slow way down. The aprons also get damaged by the
| heavy trailers since they're not built to the same standards
| of roadways.
| LinuxBender wrote:
| _Should traffic lights be abolished?_
|
| No. Phased out over time in some places maybe, not abolished.
| Implemented in some new developments, absolutely.
|
| While roundabouts can work more efficiently they require the
| roads and traffic usage patterns to accommodate them.
| Additionally existing intersections designed for lights and
| putting in roundabouts would require cities in many cases to use
| eminent domain to acquire the land around them or to buy out
| land/properties from people. The excessive use of eminent domain
| would lead to endless legal battles that would deplete city
| budgets.
|
| Some existing large intersections could be retrofitted for a
| roundabout and some small cities are in fact doing this. I've
| also witnessed this occurring in rural areas that have
| intersecting highways where the state already owns the land
| around the highways. This reduces brake dust, engine brake noise
| and keeps freight moving.
| bubbleRefuge wrote:
| Didn't read the article but flyovers maybe expense but can get
| the job done. Wish there were more of them at major
| intesections
| andsoitis wrote:
| Concur with your thinking.
|
| At the same time, I took "abolish traffic lights" as a North
| Star for future design as well as making changes to existing
| infrastructure where economically and physically feasible (i.e.
| stay practical). Not rip out all traffic lights everywhere and
| replace them with roundabouts or rotaries, as the case might
| be.
| gpderetta wrote:
| And then you get roundabouts with traffic lights like in the
| UK. I'm sure there are good reasons for that, but, as someone
| that hardly drives in the UK, I was very very surprised the
| first time I encountered them.
| anyonecancode wrote:
| Oh, that's nothing. Here in New Jersey, we have what my wife
| refers to as a "traffic theta". Here's an example:
|
| https://www.google.com/maps/@40.7957351,-74.3405952,17z
|
| It's a circle, with traffic light, but also still an
| intersection. Fun!
| d1sxeyes wrote:
| You generally get these when the roundabout has one or more
| clear 'through traffic' routes, to the point that you're
| always 'giving way to the right' and not able to enter the
| roundabout.
|
| If you imagine traffic on a motorway going North/South and an
| A-road running East-West, at busy times, the traffic going
| from East to West and West to East will be significant enough
| that traffic coming off the motorway is not able to find
| enough space to enter the roundabout (or, not enough to meet
| the demand). Without traffic lights, traffic will soon back
| up down the slip road onto the motorway, or worse, will try
| to force its way onto the roundabout instead of giving way to
| the right.
|
| Traffic lights make this much safer.
| alistairSH wrote:
| Or some arrangement of flyovers, ramps, etc (double diamond
| interchange being the current flavor of the month here in
| the US mid-Atlantic). Obviously, only makes sense for
| actual motorways, not going to get one in mid-town London,
| hopefully.
| avianlyric wrote:
| Land is expensive enough, and built up enough, in the UK
| that flyovers are pretty much not an option near any
| major road anymore.
|
| In general the UK has very few flyovers. I sometimes
| suspect the SF Bay Area has more flyovers than the entire
| of the UK.
| cameronh90 wrote:
| In addition, in areas with very high traffic, like London,
| area-coordinated adaptive traffic light systems (see
| SCOOT/SCATS) are used to keep traffic flowing smoothly, stop
| congestion from blocking junctions, prioritise emergency
| services and more. These systems are very good at what they
| do.
|
| Traffic lights are also used to give priority to pedestrians
| and cyclists on junctions where it would be unsafe to rely on
| zebra crossings or pedestrian priority - think sharp and low
| visibility corners.
|
| As far as roundabouts go, the UK has been replacing big
| multi-lane roundabouts in areas with lots of pedestrians and
| cyclists with two-way-traffic horse shoes (e.g. Old Street
| and E&C, plus others outside of London). This allows the
| centre of the roundabout to be used as public space, and has
| been found to be safer for vulnerable road users.
|
| I'm all for light-free junctions where possible, and light-
| free roundabouts work REALLY well in low/medium traffic. But
| you can't just abolish traffic lights - unless we also
| abolish cars at the same time.
| wizofaus wrote:
| Do you have a link to one of these "two-way horse shoes" on
| Google maps or similar? I'm curious how they solve the
| problem of needing to taking the 3rd exit on a multi-lane
| roundabout while on a bicycle.
| avianlyric wrote:
| Pretty simple. The section of road between 3rd exit and
| the 4th (which is also where you enter) is completely
| removed.
|
| So taking the 3rd exit on a bike either means following
| the road all the way around, or just going directly from
| the entrance to the 3rd exit, as cycle lane is usually
| preserved where the road used to be.
| wizofaus wrote:
| I looked at that E&C "horseshoe" - it still looks hairy
| if you're riding north on the A3 and want to turn right
| into the A201, given the number of crossings of busy
| roads with no traffic signals. But better than some of
| the busy 3-lane roundabouts I've had to navigate here
| with no provision for bicycles (or pedestrians really) at
| all.
| cameronh90 wrote:
| Look up the Old Street roundabout and Elephant and Castle
| Roundabout.
|
| The essence of of is segregated cycle lanes with cycle-
| only traffic lights. Nothing magic.
|
| Neither of them are fully separated (yet at least -
| they're still being worked on), but they're a lot better
| than what came before.
|
| Trafalgar Square also used to be a roundabout back in the
| day, though it got converted to a peninsula before
| bicycles were fashionable so that's not a great example.
|
| Highbury Corner is another example you can look at.
| wizofaus wrote:
| Highbury looks to solve it by having traffic lights
| explicitly for pedestrians/ bicycles to cross at?
| taylodl wrote:
| My city has been going roundabout happy over the past few
| years. One issue they've had to contend with is existing
| intersections in congested urban areas don't have enough space
| to replace with a roundabout. Therefore it's been primarily the
| suburban areas that have been able to implement them.
| pjc50 wrote:
| The UK "mini-roundabout" does not take up additional space.
|
| Roundabouts work best when the traffic is below a certain
| critical level; above that and you're still stuck for ages
| except with no automated system trying to bring "fairness". In
| some cases this can be solved by .. adding traffic lights to
| the roundabout.
| moonchrome wrote:
| Yes, they recently rebuilt a large roundabout here - it
| connects two busiest roads in town - it was nerve-wracking to
| enter on a motorcycle before. Now they rebuilt it with trafic
| lights and a straight lane underpass for the main road and
| it's much more pleasant.
| rascul wrote:
| > The UK "mini-roundabout" does not take up additional space.
|
| There are plenty of small intersections with traffic lights
| that aren't any wider than two opposite lanes with no median
| and no shoulder, only big enough for two vehicles to pass in
| opposite directions. They would need to be expanded to put a
| circle of any size in the middle, especially if a big truck
| was expected to make it through safely.
| mdpye wrote:
| A mini-roundabout is a centre circle painted (not curbed),
| plus the priority rules (give way to your right - would be
| your left in the US).
|
| They don't take up any extra space, but they _do_ probably
| require drivers to intuitively understand the concept and
| priorities before they can be introduced.
|
| Here's a satellite view of a random one near me:
| https://goo.gl/maps/NJ2KpYdMP1reQA1u5
|
| Its an upgrade of the American 4-way-stop with better
| defined priorities for entry.
| cogman10 wrote:
| Yeah... I don't think those will work in the US until
| roundabouts are a lot more common.
|
| The issue I've seen with them in the US is many US
| drivers ignore pretty much everything about the painted
| circle which creates a really dangerous situation. They
| treat those intersections like 4 way stops (including
| driving over the circle) and that's a major problem.
| drewzero1 wrote:
| Not to mention that in large areas of the northern US,
| any painted road markings are likely to be covered by
| snow and ice a good portion of the year.
| genocidicbunny wrote:
| That definitely takes up extra space. Notice all the room
| between the lanes. In many places in the US, you don't
| have even that. The intersection is literally only wide
| enough for two cars to go past each other, and _any_
| amount of space taken up in the center means you need to
| widen the road.
| [deleted]
| alistairSH wrote:
| Here's another one from Scotland. They don't have to take
| extra space. The version shown above only has extra space
| because they installed pedestrian islands - a nice touch
| but not required in many intersections.
|
| Additionally, there is frequently extra space in the
| existing intersection. From parking lanes, shoulders,
| etc.
|
| https://www.google.com/maps/@56.5902318,-3.3376212,3a,75y
| ,34...
| genocidicbunny wrote:
| This is a much better example, thanks. That does indeed
| look like it doesn't really take up any more room -- the
| painted roundabout mostly seems to serve as a reminder of
| the yield order that people should take. In a way, its
| almost like a yield-controlled intersection here in the
| US. Those work relatively well as long as everyone
| follows the rules. In many places, this would just be
| inviting aggressive drivers to blow through
| intersections.
| alistairSH wrote:
| Exactly.
|
| Worth noting this particular roundabout is in a small
| farming town on the edge of the highlands. Already slow
| speed road and low volume. But, shows that many 4-way
| stops within the US suburbs could easily be swapped with
| a roundabout during normal road repaving without much
| additional cost (yield signs to replace stops, some
| paint).
| rascul wrote:
| You're still supposed to drive around the circle though,
| right? Or am I misunderstanding?
|
| That intersection you showed is clearly big enough. This
| one doesn't look big enough. Or is it? There are smaller
| intersections than this one, also. (And I realized that
| this one might be a bad example because it's not four
| directions.)
|
| https://goo.gl/maps/fBEysywZgdQVWH7N9
| ben_w wrote:
| The north and south exits to the roundabout are 10.5m
| across, including the traffic islands; the west exit is
| 5m across. The 4-way junction you've linked to, the exits
| are 9.5-11 meters across.
| alistairSH wrote:
| At some intersections in the UK, the roundabout is
| literally a small circle of paint. The car doesn't really
| go "around" it because it's so small. It mostly exists as
| a visual cue that the intersection follows roundabout
| rules.
| rascul wrote:
| Ok, I was working under the impression that one must
| drive around the circle. If that requirement isn't there
| and it just changes how we work out who goes when then I
| can see that expansion wouldn't be necessary.
| graton wrote:
| One of the large benefits of roundabouts is the reduction in
| serious crashes. 90% reduction in deaths, 76% reduction in
| injuries, and 35% reduction in all crashes. [1]
|
| 1) Cars need to slow down to go through the roundabout safely, 2)
| If there is an accident it is more of a side-swipe type accident
| than a t-bone or head-on accident.
|
| But as others have said they aren't the best solution for all
| situations but they could be used a magnitude more than they
| currently are here in the U.S.
|
| [1]
| https://www.oregon.gov/odot/Engineering/Roundabouts/Roundabo...
| trgn wrote:
| Yes. We should start everywhere with turning them off and
| introducing four way stops. Then re-assess which intersections
| need that light, or need a roundabout.
|
| Traffic lights invite aggressive driving because drivers want to
| make it through the green (or orange) light. Basically, drivers
| end up accelerating into the intersection, rather than slowing
| down and be more careful. It's the _exact_ opposite of what
| should happen.
|
| Traffic lights are the result of a misplaced obsession with
| efficiency and high technology. The idea we can perfectly manage
| complex systems (very mid 20th century mindset). We need a value
| shift. Safety is more important than speed.
| rascul wrote:
| I've found four way stops to be dangerous and unpredictable
| with more than two lanes each way.
| oangemangut wrote:
| mostly agree but as other posters have mentioned I would
| imagine that any crashes that occur in in mulit-lane 4-ways
| are likely to be less severe/likely to injure people.
| booboofixer wrote:
| Came here to comment this. I've seen two-lane stop signs and
| if you imagine traffic on all four sides, just think of the
| number of other drivers you have to coordinate with if nobody
| is sure who has the right of way.
|
| I've also seen two lane roundabouts which aren't bad, but now
| there are roundabouts where you go from two to one, or two to
| three lanes driving inside the roundabout! Definitely safer
| than stop signs but the most un-intuitive intersection for
| new drivers.
| trgn wrote:
| Yes, I'd agree. Let's start with reducing those to two lanes
| then as well :)
| abfan1127 wrote:
| no, traffic lights are efficiency.
|
| Traffic is easily modeled as buffers and context switching. As
| traffic flows through an intersection, the buffer for that
| direction drains. When it switches, there is a penalty to
| context switch (the traffic must come to a stop, some traffic
| must finish through the intersection). The perpendicular buffer
| (which has been filling), requires the intersection to clear
| completely before proceeding. Then its buffer can empty.
|
| 4-way stop signs introduce context switching for every car (the
| intersection must clear before proceeding) and you must stop
| every intersection, buffer stalls.
|
| Round-abouts ensure more rapid context switching (only wait for
| the car to your left to clear), no waiting for an empty buffer
| to continue to be empty, and fewer buffers per intersection
| (think left turn buffer, right turn buffer).
| hedora wrote:
| > _no, traffic lights are efficiency._
|
| Yes, but:
|
| https://xkcd.com/277/
|
| Around here, typical light cycles are 2-3 minutes, and
| intersections often sit idle for 60+ seconds. When there are
| power outages, and the lights switch to four way stop mode
| (blinking red), traffic usually improves. Also, the
| California state government has basically mandated programs
| that intentionally increase congestion.
|
| They call it traffic quiescing, or say they want to reduce
| commute miles driven per year. No, they aren't providing
| meaningful improvements to public transit or bike safety.
| pmontra wrote:
| Efficiency, well... Sometimes / somewhere they seem set up to
| maximize driving time and pollution by turning the next light
| to red when one has just gone green. I wish they could use
| computer vision to turn traffic lights to red only when two
| cars approach the intersection from perpendicular directions.
| abfan1127 wrote:
| traffic lights in my old city did just that. Cameras
| monitored intersections and switched lights accordingly.
| trgn wrote:
| > no, traffic lights are efficiency.
|
| That's exactly what I said. Traffic lights for governing car
| traffic are the result of a modernist obsession with
| efficiency; in this case a pre-occupation with car travel
| speeds, throughput, ... as if these are the only things that
| matter. I gather you view that as a positive, but I see it as
| a very impoverished monomaniacal mindset. That technocratic
| value system has poisoned (literally and figuratively) the
| public realm. We need less of it.
| abfan1127 wrote:
| travel speeds and throughput aren't necessarily related.
| Recall that car spacing is usually instructed to be "2s".
| the throughput is 1 car/2s. thats regardless of speed.
| Speed dictates the length of the yellow light, often about
| 1s for every 10mph, but the actual throughput is the same
| regardless of speed.
| smileysteve wrote:
| The automatic transmission should be abolished first. And all
| energetic cars should be in golf cart pedal mode.
|
| Whether it's on the highway or around neighborhoods with speed
| bumps and pedxing, you see (and hear) cars speeding away only to
| endanger the next person at the next stop sign or traffic light,
| or car in front of them.
|
| (I can "1 pedal drive" my manual down a hill in 2nd or 3rd, go a
| reasonable speed, automatically be slowing to go over a speed
| bump)
| JetSetWilly wrote:
| I live in the UK which is primarily manual cars. Trust me that
| plenty of people race between speed bumps and pointlessly go at
| max speed to a visible red light hardly any distance away. I
| doubt the gear box is making much difference to whether people
| want to be selfish and discourteous or not.
| wizofaus wrote:
| Wow, I just looked it up and 70% of cars in the UK are still
| manual "stick shift" transmission. Though for new car sales
| it's slightly below 50%. Compare Australia where at most 25%
| or so of vehicles currently on the road are manual (*), and
| barely 3% of new car sales are. Obviously will become
| irrelevant with EVs.
|
| (*) actually I couldn't find an official stat for this. The
| number of registrations is slightly higher but a fair number
| are "collector" cars that are very rarely driven, or mostly
| in very rural areas. I'd actually suggest in the cities where
| the vast majority of us live, among cars that are driven
| regularly manual transmission is a good deal rarer, certainly
| less than 20%.
| 2rsf wrote:
| Many electric vehicle can do 1 pedal drive, but what is the
| gain? I once calculated for my Polestar that it can save
| something like 1 meter of braking distance or less from
| 100km/h, so not super impressive.
| rhn_mk1 wrote:
| What is "golf car pedal mode"?
| smileysteve wrote:
| 1 Pedal driving, ie, regen brakes apply whenever there is no
| pressure on the gas.
|
| In a manual transmission this is from engine braking, without
| gas applied, it immediately starts slowing down.
|
| This makes traffic flow better by reducing the need for last
| minute stopping, predicting when you need acceleration,
| reducing speed automatically when the driver is cautious, and
| generally increased attention and awareness.
| trgn wrote:
| I have no idea with pedal driving is, but if you mean that
| traffic lights invite that pathetic type-A kind of driving,
| accelerating to the next lights only to immediately have to
| break because the next light is turning red, yes, that's
| totally dumb and needlessly endangering others. Drivers should
| totally smooth out their speed, slow acceleration, slow
| deceleration. When you drive like a gentleman, you'll find out
| you rarely have to break.
| strken wrote:
| Roundabouts are great on back streets where you'd naturally be
| going slowly, and okay on the meeting point between two major
| roads, but in my extremely limited experience they don't work so
| well in the case where you have a major road (light would usually
| be green to let large amounts of traffic through) crossed by a
| street (light would usually be red, intermittently green for a
| few cars).
|
| Perhaps in that case you're meant to use overpasses, or maybe the
| data says that roundabouts work fine, but they don't seem to.
| gumby wrote:
| California made a (tiny) push into roundabouts a couple of
| decades ago, but for some inexplicable reason usually pair them
| with stop signs. What's the point?
| professoretc wrote:
| The only roundabouts I've seen in CA with stop signs are the
| big ones (like the "traffic circle" in Long Beach) where the
| roundabout is almost a street unto itself.
| gumby wrote:
| Come to Palo Alto where they are equipped that way on small
| residential streets!
|
| Massive ones like you describe don't need stop signs.
| anonporridge wrote:
| "Tell me you don't understand roundabouts, without telling me
| you don't understand roundabouts."
|
| California: "Hold my kombucha."
| coding123 wrote:
| I love how people say "abolished" so easily and don't realize the
| magnitude of change it would require. /aside
|
| In any case, Arizona has a LOT of roundabouts. They take
| considerably more land so it would basically be impossible for
| the vast majority of existing in-city street corners. Arizona
| uses them more in rural/not yet developed areas. Definitely help
| speed up things, but I would say at this point, it will only be
| useful for new, very spread out cities.
| ahoy wrote:
| Zero consideration for pedestrians, typical of US traffic
| engineering. Sucks here.
| autokad wrote:
| yeah its 2020 thinking "I believe X so everyone everywhere
| should always have to do X".
| balozi wrote:
| There are tons of roundabouts that have traffic lights too.
| samcat116 wrote:
| Those are generally rotaries, not roundabouts.
| aareet wrote:
| I've discovered the game Mini Motorways on Apple Arcade recently
| and this has opened my eyes to how much more efficient
| roundabouts are in traffic management :) I've been enjoying the
| game a lot! It's a very enjoyable thought experiment made into a
| game. If you haven't tried it, I'd recommend it.
| cameronh90 wrote:
| Traffic lights aren't the main problem: four way intersections
| are.
|
| Roundabouts, offset T-intersections and grade separation all make
| traffic safer by removing conflict points - it's not the removal
| of traffic lights that improves the safety. Four way
| intersections put traffic directly on collision paths at high
| speed, meaning if anyone makes an error (missing the light or
| otherwise), you have an awful crash.
|
| It's relatively rare in the UK to have four way stops or high
| speed four way signal controlled intersections. One of the weird
| things about driving in the US for me was the prevalence of both
| of those things.
| palmetieri2000 wrote:
| This the most salient point to me, it is absolutely
| unbelievable to me that the US continues to use four-way
| intersections despite the huge risk, loss of life and suffering
| they cause. They are exceptionally rare in Australia too, if
| they do exist it is only on a road with a speed limit of 60km/h
| (at least in my region).
|
| Coincidentally, where I live is known for its many many
| roundabouts and not only are they safer but they also offer
| superior cross-way throughput when traffic is heavy. And they
| allow the "middle" of the intersection to store a chunk of
| traffic who are protected from full speed impacts while still
| letting vehicles flow slowly through the perpendicular axis.
| thanatos519 wrote:
| It works in some places. This intersection is way, way better to
| walk and cycle through since the traffic lights (and all signs!)
| were removed, and I have never seen cars stuck or delayed:
|
| https://bikecity.amsterdam.nl/en/inspiration/experiment-traf...
| MiddleEndian wrote:
| https://en.wikipedia.org/wiki/Kelley_Square
|
| Adding some sort of pseudo-rotary has made Worcester,
| Massachusetts's Kelley Square go from Massachusetts's most
| dangerous intersection down to its eighth most dangerous
| intersection lol
|
| Somehow still never had any traffic lights at any point.
|
| Before:
| https://www.wbjournal.com/sites/default/files/2019-10/kelley...
|
| After: https://www.gannett-
| cdn.com/presto/2020/12/31/NTEG/86da81b0-...
| xani_ wrote:
| No wonder, they added a nice straight for cars to speed up
| before the other cars merge into it.
| wolpoli wrote:
| It looks like they reconfigured the intersection into a
| roundabout, which eliminated the weird geometry of the previous
| design and reduced the options available to drivers to just
| entering and exiting roundabout.
| spaceman_2020 wrote:
| In my neck of the world, the traffic cops, for some reason that I
| can't even fathom, switch off traffic lights after 11pm at a lot
| of major roads.
|
| It doesn't lead to as many accidents as you'd think, but boy is
| it a nerve wracking experience crossing these roads at night.
| ezfe wrote:
| They do this for us as well, no reason not to. Otherwise you
| just sit there for a while when nobody is coming.
|
| They switch to blinking red / blinking yellow to indicate stop
| / yield.
| giantg2 wrote:
| We have some that turn into flashing yellow for the main road
| and flashing red for the secondary.
| dncornholio wrote:
| The Netherlands is stuffed with these things. The amount of
| traffic lights I have to go trough to get to work is: 1. This is
| a 30km trip from town to town.
|
| The only part of my route that I always have to stop, is the
| traffic light. Roundabouts are awesome. Our complete
| infrastructure is pretty awesome to be honest. Other countries
| could learn.
| tengbretson wrote:
| It'd be nice if the people installing roundabouts in the United
| States could stop their habit of splitting lanes of traffic into
| multiple lanes, each with different rules for which direction you
| can exit with about 20 feet of notice before you enter.
| JoshuaEddy wrote:
| This is a feature, not a bug. Once you learn the general
| philosophy, you will be fine. For a 2-lane roundabout: Use
| right lane if you want to turn right. Use left lane if you want
| to turn left. Either lane is fine if you want to go straight.
|
| It's like when you approach a traditional 4-way intersection,
| some of which add a left-turn-only lane and some of which add a
| right-turn-only lane: once you learn the general philosophy,
| you will be fine.
| autoexec wrote:
| > It's like when you approach a traditional 4-way
| intersection, some of which add a left-turn-only lane and
| some of which add a right-turn-only lane: once you learn the
| general philosophy, you will be fine.
|
| Those bug the shit out me to too. Sure, you get used to them
| quickly enough when you drive on those roads all the time,
| but everyone who hasn't encountered it has to figure it out
| and depending on how well marked it is even people familiar
| with the rules have to deal with confused people who haven't
| figured it out yet.
|
| I especially hate those left-turn-only lanes which leaves
| people who could have turned right on red stuck behind people
| who just want to go straight. The people who want to go
| straight would have to wait for a green light anyway, so why
| not leave them stuck behind the left turners who also have to
| wait and let traffic flow for the people making right hand
| turns?
| jsmith45 wrote:
| I agree with that. I used to be one of VERY, VERY few
| drivers that ever when straight at a certain intersection
| with a left turn only lane, and a straight and right turn
| lane. The other direction was bigger, and there was a
| relatively long wait for the light to change once a vehicle
| detection was triggered. I always felt bad for the people
| behind me because I was blocking from making a right on
| red.
|
| It would have been so much better if it was a right only,
| and straight+left lane.
|
| There is of course an exception to this. If there is a
| protected left turn cycle, then the left turn lane needs to
| be its own lane, but that was not the case at the
| intersection in question.
| tengbretson wrote:
| > For a 2-lane roundabout: Use right lane if you want to turn
| right. Use left lane if you want to turn left. Either lane is
| fine if you want to go straight.
|
| This is simply not universally true. I've seen roundabouts
| with different lane routing assignments even within the same
| neighborhood. It's incredibly hostile to visitors.
| professoretc wrote:
| > could stop their habit of splitting lanes of traffic into
| multiple lanes
|
| Even worse are the roundabouts that are _wide enough_ for
| multiple lanes, but with no lane markers. Just kind of a
| circular flood of cars, with people on the inside suddenly
| realizing they need to get off, etc.
| thatguy0900 wrote:
| All the roundabouts near me certainly have to already be known
| to use them. You can tell how many people are just passing
| through every time you use them as they hurriedly weave in and
| out of lanes
| Neil44 wrote:
| I grew up near Skelmersdale which is a 'new town' built in the
| 60's without traffic lights, all roundabouts. Traffic is
| segregated from pedestrians using underpasses and footpaths don't
| follow roads generally. Some aspects of it work well. It's
| pleasing and efficient not to have to stop much when you're
| getting places. The underpasses have become magnets for anti
| social behaviour though.
| gumby wrote:
| The mistake is that the _cars_ should use the subways
| /underpasses since they are inherently antisocial already. The
| antisocial types can then all hang out together.
| wizofaus wrote:
| How does that work for bicycles? As a cyclist most roundabouts
| are OK but busy multi-lane ones can be pretty terrifying if you
| need to turn against the traffic flow (i.e., taking the 3rd
| exit, right for me, but left if in the US or any country you
| drive/ride on the right side of the road). I've yet to see a
| decent solution to that.
| cortesoft wrote:
| I am curious at what traffic levels roundabouts stop being more
| efficient. I know in Cities Skylines, the roundabouts will
| deadlock over a certain traffic level.
|
| Like, would roundabouts work on the 4 lane roads that are always
| packed with traffic here in Los Angeles?
| bsagdiyev wrote:
| Doubtful. The roundabouts placed in some places in the IE still
| had people going the wrong way and just generally not
| understanding how they worked. You'd need to do education along
| with implementation for something like that to help.
|
| Personally I doubt it would help traffic in any significant
| manner but who knows.
| toast0 wrote:
| Roundabouts are best with a range of traffic from very sparse
| to intermittent. Always packed from all directions doesn't work
| because throughput is structurally limited and worst case wait
| time is infinite. It's kind of like a cloverleaf junction, very
| functional until you hit capacity limits, then not very
| functional.
|
| In most of the Los Angeles area, there's not room to
| drastically expand intersections to build usable roundabouts,
| compressed roundabouts are even worse at throughput.
|
| Multilane roundabouts exist, but they're tricky to navigate and
| would be tough to have high throughput for if most people want
| to continue traveling in the same direction after the
| intersection.
| bombcar wrote:
| I've seen huge roundabouts with traffic lights and crossing
| lanes and all sorts of fun stuff.
| toast0 wrote:
| Well, a roundabout with a traffic light is hardly
| aboloshing traffic lights.
| alistairSH wrote:
| A nice visual showing why roundabouts are usually safer than
| simple intersections... https://nextstl.com/wp-
| content/uploads/9577583353_3c13fe8144...
|
| [the triple pedestrian conflict at each entry threw me at first -
| but if you consider where the driver is likely looking, it makes
| sense]
| fnordpiglet wrote:
| I find the traffic roundabouts a great solution for seattle
| residential streets. It allows a slow down through the
| neighborhood, a way to negotiate the four way intersections, and
| helps with the narrower than normal roads.
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