How's called the inverted lane in your country?

[An_dz]

I was driving around here in Brazil when I saw one traffic sign showing a road have inverted lane system, drive on the left rather the right. And here we call them British Lane roads.

So I was wondering how it's called in other countries, specially UK.

That's my question for you. Show us how your people call this.

[Isaac Eiland-Hall]

I'm not aware of a term for that here.

I am aware of Contraflow, which is what they do when they need to evacuate coasts for an incoming hurricane: http://en.wikipedia.org/wiki/Contraflow

[Zeno]

Never saw one of those in Spain, probably we don't have such lanes...
Btw, we already drive like idiots by the right one, such inverted lanes would be chaotic here!

[prissi]

I was not aware that there such roads exist in the world. How does the corssing of lanes work? And what is the advantage for such a dangerous exercize?

I am pretty sure this does not exist at least in germany.

EDIT Maybe sweden had something like this, since they switched 1967 or so from left to right side driving.

[Sarlock]

Interesting.  No lanes/roads that I know of in Canada that are reversed like this... I'd be interested as well to know why this is done.

[Combuijs]

Never seen it in the Netherlands too. There is no name for it as far as I know.

[ӔO]

sometimes you can get reversed lanes in a highway if it has a diverging windmill interchange or diverging diamond.

[IgorEliezer]

I am aware of Contraflow, which is what they do when they need to evacuate coasts for an incoming hurricane: http://en.wikipedia.org/wiki/Contraflow

Technically, contraflow (or counterflow) best fits the term we Brazilians use for "Contrafluxo" since "fluxo" is "flow", and "contra" is used in both languages. There is the Reversible lane. But both cases aren't what An_dz is talking about. I'd call it "Inverted-traffic lane" or "Inverted-way lane".

Try also: http://en.wikipedia.org/wiki/Category:Types_of_roads, and http://en.wikipedia.org/wiki/List_of_road_types_by_features

I was not aware that there such roads exist in the world. How does the crossing of lanes work? And what is the advantage for such a dangerous exercize?

I lived in two cities that had (or still have) this kind of system, not one lane with inverted ways, but two separated lanes with inverted ways. That happens for lack of available space to build proper intersections or double-lanes or because the regions that generate or attract the traffic are in regions that a "normal" system is not suitable.

For example, we use right-hand traffic as standard. This means that, the traffic goes on the right-hand and returns on the left-hand. Say, during the morning rush-time the traffic mostly goes from an main avenue to the district "A", and during the evening the traffic comes from the district "B" to the main avenue, but there's a problem: the district "A" is on the left side of the access way, and "B" on the right side. Solution: invert the ways. (To be honest, I don't recommend it. This rather seems a half-yummy solution)

[An_dz]

Interesting, I didn't expect it being so rare around the world.

(I don't recommend, to be honest)

The architect and urban planner is saying. No discussion here.

I was not aware that there such roads exist in the world. How does the corssing of lanes work? And what is the advantage for such a dangerous exercize?

A road don't simply become inverted in the middle of nothing. Or it's always inverted lane or it's between crossings.
Mostly they are used between two one-way lanes, each going on inverse direction, it's 'safer' and 'easier' to go to the other direction. If in a crossing one side is inverted and the other don't. You simply can't cross.
But the most variable lane designs exist.

[IgorEliezer]

Interesting, I didn't expect it being so rare around the world.

Okay, I give up. We have to admit our country is a bit strange and pretty sui generis.

[wlindley]

There is a relatively recent discussion of contra-flow lanes here.  They are highly unusual in North America, and the thread catalogues perhaps the dozen or so which exist on that continent.

[Isaac Eiland-Hall]

tired after a long day, but I am also aware of a couple of places ( can't remember where, no energy to find) where there are short distances of a block or so with lanes in the 'wrong' sides - for various reasons including bus routes and just the layout of the streets for whatever reason - read an article a while back, but can't remember where...

[ӔO]

There is one place in toronto that has two roads running parallel to each other. Now, that may sound normal, but this one is only separated by a central divider.

To cross on to that road, you need to stop in the middle of the road, wait for the lights to change, and then cross over when the lights allow. What is worse, is just down the road, that street ends and becomes a nightmare intersection for many to navigate.
http://www.blogto.com/city/2011/05/the_worst_intersections_in_toronto/

That second intersection listed is pretty interesting, if you look at it from a top down view.

[sdog]

I've seen something similar, but can't recall where. It was practically just two one way roads joining and diverting again. In such a way that they were adjoint for a short stretch in the wrong order.

-->--\       /--->
         ===
--<--/       \-<---

However both roads were seperated in the middle by barriers. It wasn't so much a reversed direction road but rather two one way roads at a very small distance.


@ӔO: Surprisingly i know all of them. Most of the time such trafic posts are about places far from my home. Dupont-Anette and Dundas made me wonder who on earth would plan such a thing. (and it looks like there was quite a bit of money invested in it, lots of concrete.)

Bathurst and Lakshore, Fleet is a real pain to cross as pedestrian. But the difficulty of most others seem to be only that they are not intersecting at a right angle :-P

The pedestrian accident lists seems to correlate with number of pedestrians crossing. Spadiana & Dundas is likely the busiest crossing in canada.

[Lmallet]

tired after a long day, but I am also aware of a couple of places ( can't remember where, no energy to find) where there are short distances of a block or so with lanes in the 'wrong' sides - for various reasons including bus routes and just the layout of the streets for whatever reason - read an article a while back, but can't remember where...

http://www.divergingdiamondinterchange.org/

A few American states have been trying out diverging diamond interchanges, where traffic flips from right to left before an interchange, then flips back from left to right after the interchange.  The lane crossing is controlled by traffic signal.  The idea is that you eliminate the need for 270 degree circular ramps, since traffic is always on the "right" side of the highway for a straight ramp, therefore saving space.

PS:  and for you Toronto folks:  http://www.westlansing.ca/Resources/Forms/Documents/401-Double-cross-over-Diamond-concept-Executive-Su.aspx (will open a PDF document)/

[ӔO]

@ӔO: Surprisingly i know all of them. Most of the time such trafic posts are about places far from my home. Dupont-Anette and Dundas made me wonder who on earth would plan such a thing. (and it looks like there was quite a bit of money invested in it, lots of concrete.)

Bathurst and Lakshore, Fleet is a real pain to cross as pedestrian. But the difficulty of most others seem to be only that they are not intersecting at a right angle :-P

The pedestrian accident lists seems to correlate with number of pedestrians crossing. Spadiana & Dundas is likely the busiest crossing in canada.

Dupont-Anette and Dundas, there used to be bridge that went over the tracks from old weston. With the bridge, the intersection made sense, but without it, it is just a headache. I'm used to it, since I live near there.

[sdog]

Been there a few times for walks last summer. It's close to Landsdown and Wallace, where i get bacalhau a bras occasionally on wednesdays.  Seems we're almost neighbours, just 3 km or so apart.

[dom700]

http://www.divergingdiamondinterchange.org/

Okay, Im sorry, but this is the dumbest idea for a highway access. The highway access, closest to me , is rather busy, but still only has one intersection with traffic lights, which only activate if traffic from my direction onto the way starts clogging up. This idea needs two "intersections" with traffic lights, working all the time, to do nothing too special. Personally, Ive never seen inversed traffic like you have been describing it. Seems to be a sign for bad planning.

[Sarlock]

The benefit comes from the lack of requirement for left turn signals to access the freeway onramps.  The idea is that while you have traffic signals at each crossing, you don't need left turn signals and so the traffic lights alternate traffic flow and keep things moving fairly efficiently.  If the signal lengths are timed well it will allow a larger volume of traffic through that area than a traditional configuration with left turn signals.  Your odds are higher that you will arrive at the intersection and have two sets of green lights and drive right on through.  This would be beneficial for busier areas with a fairly heavy traffic volume, a lot of which wants to access the freeway (and less straight-through traffic).
Interesting design.

[ӔO]

Grade separation is ideal, if there is money, however since many places don't have enough money, or space, to give to low traffic volume areas, people will come up with ideas like diverging traffic.


Rule of thumb: Whenever you see something strange or unusual in urban design, it usually means, 99% of the time, there was not enough money to fix it in the traditional manner. The other 1% is the result of some crazy city planning.

As I found out with downtown vancouver. Lots of dangerous places due to city planners not installing 4-way stop signs at poor sight-line intersections.

[kierongreen]

No places that I know of with drive on right roads in the UK. Contraflows, where one carriageway of a motorway or dual carriageway is closed due to roadworks and the traffic uses the remaining carriageway are still drive on left. Sometimes at motorway junctions carriageways maybe arranged such that they are the opposite way round from usual, but within each carriageway you will still have slower traffic on the left and faster on the right, and the carriageways will be separated by barriers.

[Ters]

EDIT Maybe sweden had something like this, since they switched 1967 or so from left to right side driving.

Cars had to switch lanes at the Norwegian border. Possibly also the Finnish border, though that border crossing might have been too rural for lanes to exist back then. All other way in/out of Sweden was (and mostly still is) by ferry. I image the lane switching would have been a serious bottleneck if there was as much traffic back then as there is now, so the Swedes were smart in changing before it would be too costly.

[An_dz]

Hong Kong <-> China
http://mjperry.blogspot.com/2010/06/flipper-bridge-hong-kong-to-china.html

[prissi]

I googled a little, but I found no sign for it you mentioned. Could you take a photo of such an british lane sign?

[Markohs]

Here in Spain we don't use that system anywere. I only know of one intersection in Barcelona that due to the strange and exceptional intersections in the flow, has inverted directions.

http://goo.gl/maps/h5sMk

[Ters]

Here in Spain we don't use that system anywere. I only know of one intersection in Barcelona that due to the strange and exceptional intersections in the flow, has inverted directions.

http://goo.gl/maps/h5sMk

That traffic light on the left seems a bit out of place. I wonder why they have just painted stripes with a few short poles, and not a raised "island" (and put the traffic light there).

[AP]

No places that I know of with drive on right roads in the UK.

There's only one, I believe, in the UK: Savoy Court, London, drives on the right. There's a special legal dispensation/act (or something) for it. It's been grandfathered in from the days of horse drawn carriages, and has to do with acess to the theatre there I think. Pub quiz trivia question, that.

[prissi]

Here is a little more explainations: http://www.guardian.co.uk/notesandqueries/query/0,5753,-1501,00.html

[Markohs]

That traffic light on the left seems a bit out of place. I wonder why they have just painted stripes with a few short poles, and not a raised "island" (and put the traffic light there).

Here in Barcelona there is allways semaphores on both sides of the street, even if it's two-direction. They also decided time ago raised islands was not a good idea and used plastic poles to mark them, plus white stripes on the ground. There are still some isdlands remaining, but not much, I'm pretty sure it's to make easier the movement to disabled people with wheelchairs and so.

[Ters]

Here in Barcelona there is allways semaphores on both sides of the street, even if it's two-direction. They also decided time ago raised islands was not a good idea and used plastic poles to mark them, plus white stripes on the ground. There are still some isdlands remaining, but not much, I'm pretty sure it's to make easier the movement to disabled people with wheelchairs and so.

In Norway, traffic lights are usually just on the right (when only one lane in that direction) or on both sides of the lane (or lanes in the same direction), except possibly for the ones on the far side of the junction. That way they won't be hidden behind tall oncomming traffic. I know of one exceptions (there might be more), and lack of space for an island to put it on might be the reason there. In addition, there is a light on the left only at one of the four roads, and I think the light is for buses only. It is also one of the few junctions with a pedestrian scramble I know of in Norway.

[An_dz]

I googled a little, but I found no sign for it you mentioned. Could you take a photo of such an british lane sign?

Seeing that such roads are like brazilian stuff, I don't get surprised you haven't found any.

There's not a standard sign for it. Some are terribly ugly, just a yellow sign saying british hand generally used on construction when it's temporary. Like those:
img1 - img2

Other versions are like this: img3

There's also a simple version, only with arrows: img4

A more beauty version: img5

I couldn't find a sign like the ones in my city, I'll try to take a pic when I go there.
They are like the last one but they are bigger and placed in the lateral road just before the left hand road, the arrows are replaced with a curve arrow pointing where is the british hand road.

BTW, I found an euro sign for it: img6
No idea from where it is.

[sdog]

The european sign might be in ireland. I've heard there are signs near airports.

[Ters]

BTW, I found an euro sign for it: img6
No idea from where it is.

The european sign might be in ireland. I've heard there are signs near airports.

So it's not a sign indicating inverted lanes, but a sign informing new arrivals to the country which side of the road one shall drive on? Signs giving a brief introduction to the traffic rules exist at important border crossings in Norway too. I think one of the points is which side of the road to drive on. (One of the other is that headlights must always be on.)

[sdog]

I think it's not a coincidence it's next to the right lane. There it is more noticeable for drivers who just arrived and drive on the wrong side.


Btw, does the UK use road signs more similar to european or us standards? (i find the latter not very well readable btw, but that might come from growing up with european signs)

[AP]

UK signs are similar to EU signs, generally. Wikipedia has done a good job on this:

http://en.wikipedia.org/wiki/Comparison_of_European_road_signs
(scroll down the page!)

[prissi]

I really wonder about the road sign examples. 3 out of those five seems at situation where there is nearly no advantage to left hand driving, at least compared to the wicked traffic construct earlier in Canada or Barcelona.

[isidoro]

@An_dz:  OMG!  Those signs seem too small for me...  They'd have to have more colors, big letters and flashing lights...  Aren't there accidents in those roads?  What happens if I go to a party in one such street, and after a few hours, I leave the house and forget about the sign?

I imagine those streets are very short...

[An_dz]

Generally short and road sometimes have different ground paint. Generally with those light reflector on road axis all the road or with a large yellow paint on axis, like paint on middle bottom of this image. But not that large, probably 70-100cm.

[alexbaettig]

like paint on middle bottom of this image.

That's not paint – it's dirt... normally (after rain / cleaning) it's actually white.

[ekhmuel]

I know of several places in the UK (Bath comes to mind immediately) where driving is on the right, but that is due to the effect of perverse one-way systems.

And the less said of the Magic Roundabout in Swindon, the better. (Hands up who's tried it in RL - keep your hands up if you didn't hit something.)

Paul
Edit: Still keep you hands up if upon exiting, you didn't find the nearest lay-by and start sobbing.
For Non-UK residents http://en.wikipedia.org/wiki/Magic_Roundabout_(Swindon) gives you an idea. But no amount of reading about it will compare to actually trying it out.

[kierongreen]

Haven't seen the Swindon one in real life but I have cycled around the Hemel Hempstead version!

[ekhmuel]

The problem with magic roundabouts is more the intimidation value. It's like the old principle that the safer a person feels behind a wheel, the higher the death rate. Imagine - if I put an 18 inch long 2 inch wide serrated steel spike in the middle of your steering wheel so that it was pointing right at your face or heart - you'd drive REALLY carefully. But not with our airbags, roll-bars et al then a certain recklessness builds in. There is some evidence that magic roundabouts actually cut serious accidents as everyone is too intimidated to take risks. The 'old habit' of shooting along at 45mph, taking the inside track (without a moment's thought) and scooting off on the opposite side of the roundabout cannot occur.


In real-life magic roundabouts (as you've almost certainly experienced in Hemel Hempstead - it is almost identical in layout) it is easy for a real person to be distracted by the vast amount of data you must use at once though - so it pushes up the 'simple accident' rate. And it's bloody scary. In ST however, the AI system is harder to fool.


Since posting that entry last night I actually had a deep thought. Can a magic roundabout be built in ST? And if so, is it better than a basic roundabout in some situations?


I've made a few test models so far on a new map and what it appears is that it spreads the traffic across multiple routes. The reason this works is the system has 5 entrances each feeding the other four exits for a total of 20 combinations. The routing system you would use in RL to negotiate the system is identical to how ST works it out. (I.e. if you are going from the first to the fourth exit you would use a specific set of roundabouts and in that order in both RL and ST.) And each of these 20 combinations is unique and utilises the entire network between them. And you don't need complex waypoint structures in the schedule to make sure it follows the right route - it is set up by using one-way signs which then apply to all vehicles - including NPC citycars and opponents. In a normal roundabout of the same overall dimensions (it takes a space of about 20 tiles in diameter to replicate) you get all forms of jams due to there being too few intersections.


When running road routes it is all too easy to get too much traffic trying to jam down a single route even though you might have built a 'relief road' for some parts of it. (A relief road that never gets used as the routing disregards it).


Another way of looking at a magic roundabout is to view a motorway/highway interchange from the air. (Say spaghetti junction or the M4/M5 interchange near Bristol*). Look down on it and every 'in-route' can get access to every 'out-route'. On motorways and highways they need bridges though. Now look from above and make that motorway/highway junction 2D, not 3D (flatten it so roads cross over not travel by bridges) and you have a magic roundabout. (I've been comparing schematic diagrams of motorway  junctions vs. roundabouts.) What I mean here is not that the two look the same, but the same logic (unique route to each exit from each entrance) produces the same schematic for motorway junctions as it does for magic roundabouts.


* Or for that matter The junction on the Arlington side of Key bridge over the Potomac if you prefer - the world is full of junctions to choose from. (I have driven that one as well BTW, and got lost - I was trying to get to the Bull Run battlefields. They say D.C. is Hell on Earth. And you can't get out. Try as you might you find yourself driving back along Key bridge. Northwards.)

Okay you may ask - so why care anyway? I can manage perfectly well by simply building highway junctions with slipways.

Not if you don't have room for a bridge you can't. (Ends don't line up.) Or a tunnel (the city already has a tube/subway and that blocks the system). Or you have to demolish half the town to achieve it. As ST players - how many times have you had to totally 'terra form' a landscape just to get two ends of a bridge to meet?


So what use is it? Well, now imagine the roundabout is actually a one-way system you have set up in a town. (All the gaps in the roads might be filled with buildings). For example - imagine you have got a city centre with a central city block. Imagine that central block (containing perhaps a railway station or a cluster of industries) - then that is the 'central island' of the system. Then treat each route branching out from that as a mini roundabout (going round another block). This could be critical if you have lots of trucks/busses passing through the middle of town. What this does is allow us to create a 'model' for how we can set up one-way systems (model it as a magic roundabout!) I've noticed that setting up one-way systems is usually more a matter of trial and error (from reading posts here which seem to be closer to 'if it's a bit clogged, shove in a one way and hope' reply). Perhaps a 'good central theory' is needed?


Moreover, I've seen some indications (from first tests) that by placing bus stops at certain points, it provides a good 'webway' of interlinking bus routes. This seems to avoid the problems of a single massive terminus that gets overstuffed with passengers and collapses the whole system around if running the 'no overcrowding' rule (which I always do). Instead you end up with a 'collective terminus' of multiple stations and it is really hard to collapse the whole system. I'll try to write everything down once I've tried it all out - and notes on as to why things work out certain ways.


So, each if the entrance ways is a highway to another town, busses pass into town, move round the network (Say a big city centre area) placing down passengers and then head out to another town on another route. Each route will pass over 12 of the other 19 routes at some point in the system (for the mathematicians (like me ) it forms a geometric group of order 20). A single point, well chosen, could be a railway station for long-distance travel. No more than 1 interchange would be needed to get to the railway station (I've just drawn a big A2 schematic of the setup with coloured pens). A big station would of course be big enough to 'touch' many bus stops (so they are all the same stop). Pick that carefully and no interchanges are necessary (except to get off the bus and on the train.)

Quantifiable statistical results are needed first on a number of early points raised. I plan to set up a system to replicate all 20 routes. Each will be given a timetable to repeat the route 60 or 70 times (with 50 or 60 vehicles for each route consisting of vehicles of varying speeds). All the vehicles will be released at once and once the route is finished the vehicle will end at the depot. The time taken for all vehicles (crossing & re-crossing the intersection from all directions at once) to end back at the depot will be timed. (I.e. watch for the last vehicle to get back home and stop the clock). Then build a normal roundabout of similar size and repeat. Then try for a simple set of crossroads and T-junctions but no roundabout, etc.


And to think all this started with a flippant remark!


Paul

[sdog]

The most effective and efficient complex intersection i've seen was one in china, where 5 major streets mad at odd angles. No markings, no trafic controll. It worked by self organization, intense terror and ruthlessness (perhaps also homicide). In contrast, there were perfectly controlled right angle intersections, that broke completely down as soon as police was enforcing the rules, causing a complete gridlock.

i think it's their, historic, approach to what the rich, safe countries now re-discover as shared spaces.
http://en.wikipedia.org/wiki/Shared_space

[ӔO]

I think those magic roundabouts are 'scary', because some genius thought it was a good idea to make a counter flow inner ring.

If that inner ring was filled in as a park, it would be one make it less daunting to navigate.


Oh, and there is much to be said about grade separating the counter flow ring to either above or below.
but then again, this requires actual money, instead of some road paint.

[ekhmuel]

Oh I can quite agree with many of the points raised with setting up the 'shared spaces'. (Although many town councils totally ruin it by putting it in the wrong place.) We've got a shared space in King's Lynn (not in the Wikipedia article) - it is a bloody nightmare on foot or by car. And like any system, it has its proponents (who always love it) and detractors (who hate it).


And also with Aeo's notes on magic roundabouts and the 'inner ring counter-gyratory'. As a note, putting the counter gyratory on a lower/upper level also needs the building space too.


Think instead like a series of cogs. If one cog is going clockwise the adjoining must go anticlockwise.


Alternatively, https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempstead) will link you to the site of the HH 'gyratory' (as they are officially called). Take a look at the map and the picture associated directly above the map. The central island, if large enough, is like a city block. It is a two-way road, just as normal, driving on the left. Or instead imagining the HH gyratory as just another road (2-way) travelling around a large park (the central island) with six mini roundabouts at the six corners.


In ST something is a roundabout only because one-way signs make it so. In RL, something is a roundabout only if someone says it is so. Then does the Inner London Ring road count? It goes right round the capital precinct from King's cross to Hyde Park to Victoria and Pimlico around Southwark and back through Tower Hamlets to King's Cross. It is a roundabout. It is also a two-way road - the inner carriageway of which is travelling counter-clockwise! And it has 18 mini roundabouts and 14 large ones. Look again at the map of Hemel Hempstead.


What makes Swindon difficult incidentally is that the central island is so small the next mini-roundabout is just 8 to 10 yards from the last.


But I do agree from a driving point of view.


What concerns me now is not "Do Magic roundabouts work in Real Life?" As "How can we use the logic structure to build a city centre one-way system in simutrans?" ST has a core logic (often not present in RL). It doesn't care if something is counter-intuitive (the reason a real Magic roundabout is confusing).


From early testing, there may yet be hope. By modelling the city centre appropriately, a good a free-flowing system can be built. And without needing an elevated or tunnelled inner counter-gyratory, but one that actually can work at normal ground level.




Paul

[Ters]

i think it's their, historic, approach to what the rich, safe countries now re-discover as shared spaces.
http://en.wikipedia.org/wiki/Shared_space

Oh I can quite agree with many of the points raised with setting up the 'shared spaces'. (Although many town councils totally ruin it by putting it in the wrong place.) We've got a shared space in King's Lynn (not in the Wikipedia article) - it is a bloody nightmare on foot or by car. And like any system, it has its proponents (who always love it) and detractors (who hate it).

I think the closest we get around here are a few intersections in the center of town where the road surface is raised up to sidewalk level. In appearance, it's like a huge raised pedestrain crossing (itself a hybrid between a zebra crossing and a speed hump) filling the entire intersection like a pedestrian scramble (another rare concept in Norway), except without the markings. When the public asked whether vehicles had to yield to pedestrians, like in a normal raised pedestrian crossing, or if pedestrians had to wait until it was clear, like when crossing a road at places without zebra crossings, the authorities simply replied "You figure it out" or something to that effect. Fortunately, the road doesn't have much traffic. I use it for transitioning between cycling on the road and cycling on the sidewalk, often switching sides in the process, as there is more traffic at the next intersection.