M62 Peculiar Lane Set Up

[Duple]

I recently went M62 > M60 at Eccles Interchange here

But does anyone think the lane set up is, peculiar ?

It caused quite a mess when HGVs were trying to merge with faster moving traffic and resulted in quite a lot of brake light action as people were trying to get out of the way.

Is there a specific reason this layout exists ? It doesn't feel particularly "safe".

This example at Croft Interchange has the "opposite" layout.

[c2R]

Merging lane 2 isn't always useful as if the mainline is at a halt, fast moving vehicles can end up at a standstill while a platoon of HGVs in lane 1 continues.

A third option also used close by is to drop the second lane first, before the merge: https://www.google.com/maps/@53.5226436 ... 384!8i8192 - but this of course reduces capacity.

I presume that the designs are chosen dependent on relative traffic and HGV flows, as well as available space.

[JammyDodge]

Its likely because of the proximity of the M62 slip to the M602 and J13 slips

[Keiji]

M62 > M60 at Eccles Interchange here

I call this a left-lane merge (since the left lane merges, and the right lane joins).

This example at Croft Interchange has the "opposite" layout.

And this I call a right-lane merge, for the same reason.

Is there a specific reason this layout [the left-lane merge] exists ? It doesn't feel particularly "safe".

When I was a lot younger and a lot more stupid, I used to hate the left-lane merge with a passion. There's probably a few of my old posts lying around on this forum pronouncing just that. I felt it was just yet another unnecessary modern invention giving us a step backwards instead of forwards.

That however was a time when I had never attempted to merge from the right lane of a right-lane merge, nor had much access to any examples of left-lane merges around me at all. A lot of it was before I'd even started driving!!

The right-lane merge feels intuitive. Slow vehicles and nervous drivers will more likely be in the left lane, so they get a lane to themselves and don't have to worry about merging. Experienced, confident drivers in more agile vehicles will more likely be in the right lane, so they should be able to merge just fine. Meanwhile, with the left-lane merge, the category of drivers/vehicles who have to merge gets reversed. Clearly, the right-lane merge is better, right? That was pretty much the basis of how I saw it at the time.

In practice, it's not so simple. Let's think about the not-so-obvious benefits of the left-lane merge. The fact that lorries and nervous drivers will have to merge from the left lane isn't as much as an issue as you'd think. The lane that they're going to merge into is the other lane of the merging road, which will contain traffic that already knew they were there and should have long been preparing for them to have to merge. This results in a much easier situation than if they were merging into the main carriageway of a different road: in that case, the traffic on that road would have little idea what was coming (depending on visibility), so a lot less time to get into a suitable position to allow everyone to flow smoothly, and a lot less information on which to form an expectation of how those merging drivers would behave. Plus, in a left-lane merge, if someone really doesn't want to have to merge for whatever reason... they can simply move into the right lane before the junction instead. Finally, drivers in the right lane of a left-lane merge will often be able to move over after their lane joins and before the left lane merges to allow traffic to flow better, but have no obligation to do so, so need not worry if there's too much traffic on the right to move out safely at that point.

Now, onto the right-lane merge. The traffic in the left lane gets a lane to themselves, cool. But what about traffic in the right lane? Typically, the amount of space (and time) you have to merge in a right-lane merge - counting from the moment you have visibility of the main carriageway to the last possible moment you could move over - is far less than it is in a single-lane merge or in a left-lane merge. And what happens if you run out of space? In a single-lane or left-lane merge, it's quite straightforward to slow down or even stop if you must, or continue onto the hard shoulder if there is one if there's no safer option. But in a right-lane merge, you don't get a hard shoulder, there typically aren't any ghost islands anywhere for extra leeway, and slowing or stopping would just be asking for trouble when there's traffic all around you. These days I feel using the right lane of a right-lane merge is nothing short of dangerous, and if a lot of drivers feel the same way it may as well not be there, making capacity far less than that of a left-lane merge, never mind safety.

You can also look at where the flows end up. The right-lane merge forces lane 2 after the junction to contain traffic from both roads; the single-lane merge forces traffic from the merging road all into lane 1; while the left-lane merge dynamically and naturally scales between these options by giving drives in the right lane of the merging road the ability to adjust to the situation. c2R makes a very good point about the situation where there's stop-start traffic on the main carriageway - and the left-lane merge caters well for this by essentially operating as a single-lane merge in this situation, while the right-lane merge, as they've pointed out, results in a reverse speed differential on the merging road.

This is of course all my opinion and experience, not actual research, but since the more "obvious" right-lane merge design came first and the left-lane merge has become increasingly popular in the last few decades, I suspect the folks whose job it is to decide which of these layouts to recommend as standard probably ended up noticing similar arguments to what I've made above.

It caused quite a mess when HGVs were trying to merge with faster moving traffic and resulted in quite a lot of brake light action as people were trying to get out of the way.

I suspect it would have been more of a mess if it was a right- or single-lane merge, for reasons already explained above.

[swissferry]

It would be good to see statistics and analysis comparing left lane merge, right lane merge and pre junction merge. There are advantages and disadvantages of each of them. Maybe the best option depends on number/speed of vehicles on main line, number/speed of vehicles merging, number/speed of vehicles after merge, percentage slow moving vehicles and whether lane gain continues or becomes a lane drop within a short distance.

My experience is similar to the above posts. Being familiar with right lane merges I didn't like the first left lane merge I came across but I now slightly prefer them as they seem to have less of an affect on the main line.

Pre junction merge works well if it doesn't constrain capacity (e.g. on slip roads from traffic lights) and the slip road is long enough after the merge for traffic to get up to mainline speed.

I do wonder if we are over engineering with tiger tail merges. It makes the road feel safer but drivers cutting over them is far too common a sight. Sometime by impatient drivers but more often than not by people apparently panicking they are in the wrong lane.

Junctions have an inherent danger due to conflicting movements so maybe safety would be improved by emphasising risk, encouraging slowing down and expecting to make allowances for other vehicles. I'm not persuaded that left/right lane merges are any safer than 2 lanes into 1 at the junction which gives drivers in either lane the opportunity to merge with the main line or stay in the lane gain.

[Rambo]

I recall many moons ago that this junction used to be the opposite configuration whereby the right hand lane had to merge onto the M60 and the left lane continued on towards Worsley for a bit into it's own lane.
I'm not sure why this was altered, but the left lane merge is reasonably long giving traffic enough time to merge. I recall that when the layout was the opposite way around, you would be merging with the M60 almost immediately at the bottom of the slope and often met slow or fast moving traffic making this dangerous. I would expect that due to the poor visibility merging onto the M60 it was probably an accident black spot hence the change.

[Keiji]

I do wonder if we are over engineering with tiger tail merges. It makes the road feel safer but drivers cutting over them is far too common a sight. Sometime by impatient drivers but more often than not by people apparently panicking they are in the wrong lane.

I agree - though I'm not sure if I'd include the part about tiger tails making the road feel safer.

It makes sense to split the lanes with ghost islands if they are actually going to different destinations, or if there's a physical obstruction (e.g. retrofitting two or more lanes round an existing bridge support) - but I don't see any advantage splitting them when they're just going to merge again later, and like you say, it just seems to create panic.

A junction I've used a number of times is a perfect example, and even has a correct advance sign, showing that from a 3-lane main carriageway, there will be 2 diverges separated by a ghost island which merge later on, with none of the main carriageway lanes getting dropped, and that you want to take the first or second diverge depending on your destination - when I've driven it, I've always needed to take the second diverge, and every time, without fail, I feel anxious while passing the first one that the second one doesn't exist, until it inevitably pops into view. I have to consciously remind myself that yes it does exist every time. I'm sure many other drivers in my situation would panic and suddenly dive into the first diverge only to then have to move out again later.

Some other junctions will simply taper from nothing to a 2-lane-wide slip road with plenty of distance running parallel with a simple dotted line down the middle of it before the whole thing diverges. This lets people move into whichever lane they need straight away and I think it's a lot safer.

[Bryn666]

I do wonder if we are over engineering with tiger tail merges. It makes the road feel safer but drivers cutting over them is far too common a sight. Sometime by impatient drivers but more often than not by people apparently panicking they are in the wrong lane.

I agree - though I'm not sure if I'd include the part about tiger tails making the road feel safer.

It makes sense to split the lanes with ghost islands if they are actually going to different destinations, or if there's a physical obstruction (e.g. retrofitting two or more lanes round an existing bridge support) - but I don't see any advantage splitting them when they're just going to merge again later, and like you say, it just seems to create panic.

A junction I've used a number of times is a perfect example, and even has a correct advance sign, showing that from a 3-lane main carriageway, there will be 2 diverges separated by a ghost island which merge later on, with none of the main carriageway lanes getting dropped, and that you want to take the first or second diverge depending on your destination - when I've driven it, I've always needed to take the second diverge, and every time, without fail, I feel anxious while passing the first one that the second one doesn't exist, until it inevitably pops into view. I have to consciously remind myself that yes it does exist every time. I'm sure many other drivers in my situation would panic and suddenly dive into the first diverge only to then have to move out again later.

Some other junctions will simply taper from nothing to a 2-lane-wide slip road with plenty of distance running parallel with a simple dotted line down the middle of it before the whole thing diverges. This lets people move into whichever lane they need straight away and I think it's a lot safer.

I have made this argument many times to no avail. The rest of the world copes without the giant hatched areas, and so do several junctions in the UK: https://goo.gl/maps/EKXRmYRAwMRZpUxT9
https://goo.gl/maps/F3wPCRrp5fyces9V6
https://goo.gl/maps/wm94gcuqFXbZbdmN6

Riddle me that then.

[nowster]

I suspect the difference between Eccles and Croft is space. Junction 13 is very close by, causing considerable weaving movements. Croft has over a mile before the next junction, which allows a much longer merge for lane 2. Eccles has less than 100m.

[Bryn666]

I suspect the difference between Eccles and Croft is space. Junction 13 is very close by, causing considerable weaving movements. Croft has over a mile before the next junction, which allows a much longer merge for lane 2. Eccles has less than 100m.

Yes, even in 1971 the distance between J12 and J13 was ridiculously substandard, but at least it was offset by only being a 2+1 merge back then which had more space.

Given the queues every afternoon to join the M60 clockwise from the M602, I would actually argue it may be beneficial to remark the clockwise M60 through J12 as 2 lanes again, allowing a longer merge taper from the M602 (currently ridiculously short) and a 2+2 lane gain from the M62.

Longer term J13 needs to be closed and relocated west on the M62 to create a J11A, with link roads to the A572 and A57 respectively via a new canal crossing.

[AlexBr967]

Just have a left and right merge. Problem solved: https://goo.gl/maps/hDK4V4wyuFQasZ9D8. But really though this is a horrible merge especially with the next junction being so close.

[Bryn666]

Just have a left and right merge. Problem solved: https://goo.gl/maps/hDK4V4wyuFQasZ9D8. But really though this is a horrible merge especially with the next junction being so close.

Incidentally still can't believe the signs there still all say A1 despite it being between 10 and 15+ years since various motorway upgrades were completed.