• Our booking engine at tickets.railforums.co.uk (powered by TrainSplit) helps support the running of the forum with every ticket purchase! Find out more and ask any questions/give us feedback in this thread!

Major Road Junctions Discussion, and Comparison Between UK and Other Countries

Status
Not open for further replies.

snowball

Established Member
Joined
4 Mar 2013
Messages
7,674
Location
Leeds
That's because there is a stubborn farmer's buildings in the path of where that slip road would be.
That sound like a typical urban myth. It's far more likely to have been designed that way from the start. (There is indeed a farm there and the farmer at the time may very well have been stubborn.)
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

61653 HTAFC

Veteran Member
Joined
18 Dec 2012
Messages
17,624
Location
Another planet...
That sound like a typical urban myth. It's far more likely to have been designed that way from the start. (There is indeed a farm there and the farmer at the time may very well have been stubborn.)
There's a similar myth about the farm in the middle of the M62 between J22 & J23. The myth is that the farmer refused to move so the motorway had to go around. The truth, as far as I can find out, is that ground conditions in that area make the split necessary, and as a result the farmer chose to stay despite being surrounded by motorway.
 

Bletchleyite

Veteran Member
Joined
20 Oct 2014
Messages
97,540
Location
"Marston Vale mafia"
There's a similar myth about the farm in the middle of the M62 between J22 & J23. The myth is that the farmer refused to move so the motorway had to go around. The truth, as far as I can find out, is that ground conditions in that area make the split necessary, and as a result the farmer chose to stay despite being surrounded by motorway.

Yes, I believe that is correct, but it is a fun story :)
 

Metrolink

Member
Joined
20 Jan 2021
Messages
159
Location
Manchester
I favour whirlpools the most. There's another example where the M602 meets the M60 & M62, but they're rarer than I'd like in the UK.
I agree I like whirlpools, another example is the A5103/M60 which I use often. However this junction is restricted so traffic from the Trafford centre cant head north to Southern Cemetery. What’s interesting is that a road runs under the slips and is used by buses and is part of the NCN 85 regional and 62 (trans Pennines trail)
There's a similar myth about the farm in the middle of the M62 between J22 & J23. The myth is that the farmer refused to move so the motorway had to go around. The truth, as far as I can find out, is that ground conditions in that area make the split necessary, and as a result the farmer chose to stay despite being surrounded by motorway.
I have always found that interesting part of my regular journey to Yorkshire. I can’t imagine living there with all the noise!
 

Cowley

Forum Staff
Staff Member
Global Moderator
Joined
15 Apr 2016
Messages
15,687
Location
Devon
The junction in Plymouth, north of the city centre, between the B3413 (which was once the A38) and the A386, is also logically a cloverleaf, though a very unusual one.


It has single carriageway 2-way connections serving as both the inner loops and outer slip roads; it has sharp radii, it has roads and buildings inside the loops, and it has a roundabout on the north-west quadrant slip roads, into which a third approach road, the B3373, connects.

I claim it is nevertheless a proper cloverleaf because

a) the central reservations of the two main routes are continuous

b) it has only one bridge

c) all movements are possible between the A386 and B3413 (and incidentally the B3373)

d) right turns involve going both over and under the bridge and turning through approx 270 degrees.

Some movements to and from the B3373 involve negotiating 2.5 right turn loops each.

There was also once a seven-eighths cloverleaf on the A80 at Old Inns, Cumbernauld, but it was changed in the 1980s and again when the A80 was upgraded to M80 circa 2011.

Hm. I’ve driven that junction in every direction plenty of times and I’d never noticed that before. :)
 

ABB125

Established Member
Joined
23 Jul 2016
Messages
3,746
Location
University of Birmingham
The junction in Plymouth, north of the city centre, between the B3413 (which was once the A38) and the A386, is also logically a cloverleaf, though a very unusual one.


It has single carriageway 2-way connections serving as both the inner loops and outer slip roads; it has sharp radii, it has roads and buildings inside the loops, and it has a roundabout on the north-west quadrant slip roads, into which a third approach road, the B3373, connects.

I claim it is nevertheless a proper cloverleaf because

a) the central reservations of the two main routes are continuous

b) it has only one bridge

c) all movements are possible between the A386 and B3413 (and incidentally the B3373)

d) right turns involve going both over and under the bridge and turning through approx 270 degrees.

Some movements to and from the B3373 involve negotiating 2.5 right turn loops each.

There was also once a seven-eighths cloverleaf on the A80 at Old Inns, Cumbernauld, but it was changed in the 1980s and again when the A80 was upgraded to M80 circa 2011.
That's a rather interesting example, thanks for sharing it!
I favour whirlpools the most. There's another example where the M602 meets the M60 & M62, but they're rarer than I'd like in the UK.
I quite like whirlpools, but they do require a lot of space, and some designs (such as M25/M11) have rather sharp turns, seemingly unnecessarily. A 4-level stack (a la M25/M4) is, in my opinion, the ultimate design, it just unfortunately takes up a lot of vertical space.
You can also get cloverleaf/stack hybrids, such as M25/M40, which only have two levels at the expense of land use. We only have one sort of design if this in the UK, but in other countries there's more variation.
 

ac6000cw

Established Member
Joined
10 May 2014
Messages
3,121
Location
Cambridge, UK
Whereas Germany and USA are more simple, the British Planners are more inclusive of all the roads and different journeys. To elaborate, the junctions abroad are more geometric like the cloverleaf, the British ones are built to match the terrain or landscape, avoid certain buildings, or include other roads e.g (again) the M56/M6 junction where access is given to the A50, however it might pan out differently in different countries: they could build junctions in different positions, or avoid building junctions due to cost cutting. I would compare the UKs motorway junctions to ones of urban America e.g the Newark airport junction and lots more.
The rest of the US is more ring roads and geometrics and design, especially in medium towns or cities such as Denver or Greenville, SC is another good example. Contrastingly, when it comes to simple junctions, we build bog-standard roundabouts, we don’t really use cloverleaf junctions for small cities and towns like America.
There are plenty of 'ordinary' junctions on US Interstates and Freeways, where the exit ramps lead to Yield or Stop signs, or traffic lights, plus hybrids where the more heavily-trafficked 'town' side of a junction might have extra slip roads to improve traffic flow. They are very common in urban areas where there just isn't the space to have a more complex layout, so the exit ramp widens out into multiple traffic-light-controlled lanes at the end.

Although rare in my experience, the US does have some roundabouts (called 'circles' over there), but normally only in quieter urban areas where otherwise the road layout might need multiple '3-way stop and proceed' junctions (or traffic lights) instead. I don't think I've ever come across a 'circle' junction on a major road - it might instead be the typical wide multi-lane traffic light controlled layout (usually with all the lights hanging from a long catenary wire - or wires - strung diagonally across the junction).

The US 'right turn on red' (== left turn here) rule does help the flow at traffic light junctions quite a bit i.e. red lights mean 'give way' for right turns (unless locally prohibited by signs). It's easy to forget that as a visitor, resulting in quickly being 'honked' by the vehicle behind as a reminder :)

Whatabout the M6 in the West Midlands, that had lots of junctions close together so people would use it for very short journies, was anything done to discourage that?

Besides, the junctions aren't that close together, nowhere near as bad as most American urban motorways (apart from junctions 7 and 8).

Correct - places like LA are really bad for that, which means that the inside lanes have constantly weaving traffic when it's busy (and it always is in LA - it's just the average speed that varies with time of day...)
 

ABB125

Established Member
Joined
23 Jul 2016
Messages
3,746
Location
University of Birmingham
Although rare in my experience, the US does have some roundabouts (called 'circles' over there), but normally only in quieter urban areas where otherwise the road layout might need multiple '3-way stop and proceed' junctions (or traffic lights) instead. I don't think I've ever come across a 'circle' junction on a major road - it might instead be the typical wide multi-lane traffic light controlled layout (usually with all the lights hanging from a long catenary wire - or wires - strung diagonally across the junction).
I think I've seen plans for a large American circle interchange (what we would call a "stackabout", like the M25/A12 or A3 junction), but with the roundabout marked out as basically a continuous circular sliproad, with merges and diverges at the relevant points, rather than being marked out as a roundabout!
The US 'right turn on red' (== left turn here) rule does help the flow at traffic light junctions quite a bit i.e. red lights mean 'give way' for right turns (unless locally prohibited by signs). It's easy to forget that as a visitor, resulting in quickly being 'honked' by the vehicle behind as a reminder :)
I wonder what the implications of "left turn on red" would be if it were to be implemented in the UK? In reality it'll never happen, probably because of the issues caused with pedestrian crossings etc. (I'm sure there was a thread about this within the last year or so...)
Correct - places like LA are really bad for that, which means that the inside lanes have constantly weaving traffic when it's busy (and it always is in LA - it's just the average speed that varies with time of day...)
Although to be fair a lot of American urban motorways have multiple lane-gains between junctions, so the weaving isn't quite as bad as it could be (not that that's saying much!).
 

ac6000cw

Established Member
Joined
10 May 2014
Messages
3,121
Location
Cambridge, UK
I wonder what the implications of "left turn on red" would be if it were to be implemented in the UK? In reality it'll never happen, probably because of the issues caused with pedestrian crossings etc.
The pedestrian problem is significant (I've had the odd 'moment' with that myself, both as a driver and as a pedestrian). The other problem is visibility issues with traffic from the left, resulting in right-turners pulling out into the path of other vehicles. I think those two issues are why 'right turn on red' is not allowed at some junctions.

Although to be fair a lot of American urban motorways have multiple lane-gains between junctions, so the weaving isn't quite as bad as it could be (not that that's saying much!).
Actually I think the adding and subtraction of lanes can make the problem worse e.g. when maybe the two inside lanes become 'exit only' so if you want to carry straight on you might have to move two lanes across and shoulder your way into a wall of nose-to-tail traffic. From further back you can see interesting 'ripple' effects across all of the lanes near junctions as cars weave about.

Have you driven much in the US?
 

LSWR Cavalier

Established Member
Joined
23 Aug 2020
Messages
1,565
Location
Leafy Suburbia
Left or right turn on red is madness. In Germany the law requires one to stop and wait three seconds before proceeding, many do not stop at all. Typically a vehicle turns right on red then has to wait blocking the cycle lane, where cyclists and walkers have green!

The turn on red is not obligatory, one does not have to go, one may wait for green, if one has 2-3 seconds to spare.
 

Bletchleyite

Veteran Member
Joined
20 Oct 2014
Messages
97,540
Location
"Marston Vale mafia"
Left or right turn on red is madness. In Germany the law requires one to stop and wait three seconds before proceeding, many do not stop at all. Typically a vehicle turns right on red then has to wait blocking the cycle lane, where cyclists and walkers have green!

The turn on red is not obligatory, one does not have to go, one may wait for green, if one has 2-3 seconds to spare.

Germany has a very different system from us with pedestrian crossings which makes it work, and you just get used to it*. Their rule, and they stick to it (despite it technically being the rule here it's wholly ignored), is that if you are in a turning vehicle you must always give way to pedestrians regardless of if there's a marked crossing or not. As such, the "green man" on a crossing is basically the same as a zebra.

"Turn on red" only works if that is the case (or if you're the US you just hate pedestrians anyway).

* And then, from experience, you get *so* used to it that you come back here and nearly get run over. Oops. :)
 

cornishjohn

Member
Joined
1 Feb 2011
Messages
100
Germany has a very different system from us with pedestrian crossings which makes it work, and you just get used to it*. Their rule, and they stick to it (despite it technically being the rule here it's wholly ignored), is that if you are in a turning vehicle you must always give way to pedestrians regardless of if there's a marked crossing or not. As such, the "green man" on a crossing is basically the same as a zebra.

"Turn on red" only works if that is the case (or if you're the US you just hate pedestrians anyway).

* And then, from experience, you get *so* used to it that you come back here and nearly get run over. Oops. :)
Where I have seen "turn right on red" happening in Germany, there is also a flashing amber light on the exit road, so it really is acting as a zebra like you say.

Seem to work very efficiently in northern Germany. I've never felt unsafe crossing the roads there.
 

jfollows

Established Member
Joined
26 Feb 2011
Messages
5,757
Location
Wilmslow
The "turn on red" in the USA is, of course, not nationwide albeit widely prevalent, and I was interested to look up the laws applicable in New York state, which is only one of the US states I've driven in.
For example, there's a difference between a normal "circular" red light and a red arrow. However it rapidly became clear to me that this distinction was not understood by all drivers.
Also, the rules on giving way to crossing pedestrians are clear. However I fear that in the UK there has been far too long a period during which pedestrians crossing are treated as targets by motorists, and having to give way when turning left on red would indeed be a difficult change to implement.
Anyway, here's the text of the New York law:
(d) Red indications:
1. Traffic, except pedestrians, facing a steady circular red signal, unless to make such other movement as is permitted by other indications shown at the same time, shall stop at a clearly marked stop line, but if none, then shall stop before entering the crosswalk on the near side of the intersection, or in the event there is no crosswalk, at the point nearest the intersecting roadway where the driver has a view of the approaching traffic on the intersecting roadway before entering the intersection and shall remain standing until an indication to proceed is shown except as provided in paragraph two of this subdivision.
2. Except in a city having a population of one million or more, unless a sign is in place prohibiting such turn:
a. Traffic facing a steady circular red signal may cautiously enter the intersection to make a right turn after stopping as required by paragraph one of this subdivision, except that right turning traffic is not required to stop when a steady right green arrow signal is shown at the same time. Such traffic shall yield the right-of-way to pedestrians within a marked or unmarked crosswalk at the intersection and to other traffic lawfully using the intersection;
b. Traffic, while on a one-way roadway, facing a steady red signal may cautiously enter the intersection to make a left turn onto a one-way roadway after stopping as required by paragraph one of this subdivision. Such traffic shall yield the right-of-way to pedestrians within a marked or unmarked crosswalk at the intersection and to other traffic lawfully using the intersection.
Notwithstanding any other provision of law, any city having a population of one million or more, is hereby authorized and empowered to adopt a local law authorizing subparagraph a or b of this paragraph to be applicable within such city. Upon the adoption of such local law the exception provided herein for a city having a population of one million or more shall no longer be applicable within such city.
c. On or after the effective date of this subparagraph, the sign which prohibits such turn shall be prominently displayed from all newly installed traffic signals where possible.
3. Traffic, except pedestrians, facing a steady red arrow signal may not enter the intersection to make the movement indicated by such arrow and, unless entering the intersection to make such other movement as is permitted by other indications shown at the same time, shall stop at a clearly marked stop line, but if none, then shall stop before entering the crosswalk on the near side of the intersection, or in the event there is no crosswalk at the point nearest the intersecting roadway where the driver has a view of the approaching traffic on the intersecting roadway before entering the intersection and shall remain standing until an indication to proceed is shown.
4. Unless otherwise directed by a pedestrian-control signal as provided in section eleven hundred twelve, pedestrians facing any steady red signal shall not enter the roadway.
5. Notwithstanding the provision of paragraph two of this subdivision, no school bus, while transporting pupils for any purpose, shall be permitted to proceed when facing a steady red signal.
(e) Traffic shall obey signs requiring obedience to traffic-control signals at intersections other than those at which such signals are located. No intersection not controlled by such signs prior to the effective date of this section shall hereafter be made subject to such method of control and no ordinance, order, rule or regulation requiring such obedience shall hereafter be adopted.
(f) In the event an official traffic-control signal is erected and maintained at a place other than an intersection, the provisions of this section shall be applicable except as to those provisions which by their nature can have no application. Any stop required shall be made at a sign or marking on the pavement indicating where the stop shall be made, but in the absence of any such sign or marking the stop shall be made at the signal.
 

Bald Rick

Veteran Member
Joined
28 Sep 2010
Messages
29,070
There's a similar myth about the farm in the middle of the M62 between J22 & J23. The myth is that the farmer refused to move so the motorway had to go around. The truth, as far as I can find out, is that ground conditions in that area make the split necessary, and as a result the farmer chose to stay despite being surrounded by motorway.

There was a BBC article about this recently, with an interview of said farmer’s daughter..

 

ac6000cw

Established Member
Joined
10 May 2014
Messages
3,121
Location
Cambridge, UK
For example, there's a difference between a normal "circular" red light and a red arrow. However it rapidly became clear to me that this distinction was not understood by all drivers.
Also, the rules on giving way to crossing pedestrians are clear. However I fear that in the UK there has been far too long a period during which pedestrians crossing are treated as targets by motorists, and having to give way when turning left on red would indeed be a difficult change to implement.
In the US, I've always treated a 'red arrow' as an absolute stop for that direction i.e if it's a red right arrow then no 'right turn on red' is allowed (otherwise, logically, there's no point in having it). Full 'circular' reds I treat as an 'all directions stop' indication, unless overridden by directional green arrows (basically the same as in the UK), with 'right turn on red' allowed. But the Americans often use multiple side-by-side heads with a full set of coloured arrows (or should that be colored? ;)) on each head to provide positive directional stop & caution signals (which actually I prefer to partial i.e. green only, arrows).

As a pedestrian (apart from the complete lack of pavements along some urban roads), walking across an eight-lane wide US urban road can be a bit intimidating, even though the pedestrian crossing lights are giving you theoretical right-of-way - with a countdown timer 'helping' you along on the more modern 'Ped-Xing's :) (But a lot of that nervousness is down to the fact that the other side of the road seems a long way away when you step off the kerb...)
 

Ianno87

Veteran Member
Joined
3 May 2015
Messages
15,215
There's a similar myth about the farm in the middle of the M62 between J22 & J23. The myth is that the farmer refused to move so the motorway had to go around. The truth, as far as I can find out, is that ground conditions in that area make the split necessary, and as a result the farmer chose to stay despite being surrounded by motorway.

A myth that was in fact taught to me (Wrongly) by a primary school teacher of mine. Who also incorrectly taught me the Etymology of the name 'Bolton'.
 

Ianno87

Veteran Member
Joined
3 May 2015
Messages
15,215
It's just a part of Manchester that's been "bolted on"? :D

I was told it was because a town surrounded by hills it was "a town in a bowl" (which is nonsense).

Actually comes from Bothel-tun - a place with a dwelling.
 

ABB125

Established Member
Joined
23 Jul 2016
Messages
3,746
Location
University of Birmingham
I was told it was because a town surrounded by hills it was "a town in a bowl" (which is nonsense).

Actually comes from Bothel-tun - a place with a dwelling.
Interesting, thanks. I can see the logic of the first one (assuming Bolton's actually surrounded by hills - I'm totally unfamiliar with the local geography!). I suppose it might be easier for young people to understand - they can (presumably) see the hills and associate them with the town, whereas a "dwelling" is possibly more of an abstract concept.
 
Status
Not open for further replies.

Top