M17/M18 - Gort to Tuam [open to traffic]

busyatwork · 20-11-2014 1:35pm

antoobrien wrote: »

That is supposed to be in place at signing.

With the route known and laid out by the NRA, there is no reason short of lack of machinery & appropriate personnel that excavations couldn't have started at this stage.

As was said in another post alot of the heavy equipment in ireland was sold off and went abroad , alot of the people involved in these type of projects went abroad to seek work in this field and have jobs so I dont think alot of them will come for a 3 year project and not guaranteed long term job

Marcusm · 20-11-2014 5:12pm

munchkin_utd wrote: »

em, how do you propose they do the earth works when they can't get machines?
With shovels by hand? Maybe import tens of thousands of workers from the 3rd world to get the required scale?

Surely JobBridge could provide a few thousand, no need for shovels, hands are big enough. Roadbridge (or similar) can bring the heavy machinery later.

antoobrien · 20-11-2014 5:15pm

busyatwork wrote: »

As was said in another post alot of the heavy equipment in ireland was sold off and went abroad

I know this, I'm one of several posters that stated this.

busyatwork wrote: »

, alot of the people involved in these type of projects went abroad to seek work in this field and have jobs so I dont think alot of them will come for a 3 year project and not guaranteed long term job

And yet there have been several projects like the N5 Ballinahdreen Bypass, Newlands Cross, M11, Motorway Service Areas etc that required both people and equipment and have gone ahead.

Feed Up · 20-11-2014 5:19pm

First post so I can ask a lazy question!

Where the M6 and the M18 intersect, does anyone know what kind of junction is planned? Will it be fully free flowing (grade separated?) or will it be roundabouts/traffic lights, etc?

Or can someone point me in the right direction?

Many thanks.

L1011 · 20-11-2014 5:37pm

Feed Up wrote: »

First post so I can ask a lazy question!

Where the M6 and the M18 intersect, does anyone know what kind of junction is planned? Will it be fully free flowing (grade separated?) or will it be roundabouts/traffic lights, etc?

Or can someone point me in the right direction?

Many thanks.

Three-level stack - both mainlines free-flowing and a traffic light controlled roundabout to change from one to the other.

Feed Up · 20-11-2014 6:42pm

Thanks for the reply L1011.

Have I got this right? If I'm traveling on the M6 W and want to get onto M18 S I will have to go through a roundabout controlled by lights.

So the only benefit from this layout is that if someone overshot the exit prior to the M6/M18 interchange they can turn here instead of going to the next exit.

If they built a free flowing interchange the person above would be no worse off than they are today if they overshot the exit.

Why can't the NRA do proper free flowing junctions, particularly for motorway interchanges?

I though we would have learned the lesson about motorways, roundabouts and traffic lights at this stage.

Not to mention, well in my opinion for what it's worth, that the interchange as described by L1011 will look great to any of our European neighbours - motorway interchanges controlled by lights when they've had free flowing for decades.

L1011 · 20-11-2014 7:18pm

Yes, that's right. And yes, its a terrible junction design.

It was done so they could put a service station on it - but the service station was refused planning and now we're stuck with it!

However, its a pretty common interchange type internationally on quieter motorways which this will be, mind.

JupiterKid · 21-11-2014 1:12am

The three level stack roundabout planned for the M17/M18/M6 junction is a terrible design. It's been shown to be a problem where it was built on the UK motorway system. a parclo or whirlpool type interchange would make much more sense.

busyatwork · 21-11-2014 2:00am

antoobrien wrote: »

I know this, I'm one of several posters that stated this.

And yet there have been several projects like the N5 Ballinahdreen Bypass, Newlands Cross, M11, Motorway Service Areas etc that required both people and equipment and have gone ahead.

M17/M18 moterway is the largest moterway to be build in one contract in ireland ,between the N5 and M11 would only amount to about half or less of the M17/M18 pr2oject
The only large earth mooving company left in ireland is Wills bros and they have no involvement in this project (confirmed by one of wills top foreman)

red bull · 21-11-2014 2:50am

Ad in Tuam Herald this week WANTED LARGE QUARRY

Feed Up · 21-11-2014 11:18am

Many thanks for the replies.

spacetweek · 21-11-2014 1:57pm

Feed Up wrote: »

Many thanks for the replies.

To summarise, yes we agree it's not a good design for the junction, and the UK has problems with this junction type where they exist - but the anticipated traffic levels that will use the junction are low and certainly lower than what the UK probably experiences so although it's not ideal I don't think it will cause us any problems in practice.

busyatwork · 21-11-2014 2:02pm

spacetweek wrote: »

To summarise, yes we agree it's not a good design for the junction, and the UK has problems with this junction type where they exist - but the anticipated traffic levels that will use the junction are low and certainly lower than what the UK probably experiences so although it's not ideal I don't think it will cause us any problems in practice.

Yes its a bad design, its like everything in this country no future planning for traffic levels rising, thats when they will decide to change it at a large cost to taxpayers and disruption

Goofy · 21-11-2014 2:21pm

busyatwork wrote: »

Yes its a bad design, its like everything in this country no future planning for traffic levels rising, thats when they will decide to change it at a large cost to taxpayers and disruption

It's not the best design, but it's definitely much cheaper. I think it's safe to say that this junction won't see red cow levels of traffic in my lifetime. Why waste money on a free flow junction when its never going to be required?

busyatwork · 21-11-2014 2:30pm

Goofy wrote: »

It's not the best design, but it's definitely much cheaper. I think it's safe to say that this junction won't see red cow levels of traffic in my lifetime. Why waste money on a free flow junction when its never going to be required?

Sure if traffic levels are what there are suggesting, your right the money is better spent on more road building

veryangryman · 21-11-2014 2:41pm

Goofy wrote: »

It's not the best design, but it's definitely much cheaper. I think it's safe to say that this junction won't see red cow levels of traffic in my lifetime. Why waste money on a free flow junction when its never going to be required?

If Galway ever gets its bypass, Gluas and all that, there may be a growth in numbers travelling there/living there. Its already a decent sized place for jobs with commuters in a number of directions. That said, yes its unlikely to happen soon

Zubeneschamali · 21-11-2014 2:53pm

busyatwork wrote: »

Its like everything in this country no future planning for traffic levels rising

Have a look at this junction in Belgium: There's a big stripe of land up the middle between the motorway carriageways, and the overpasses are all wide enough. There are well grown trees in that centre divide, it was all built many years ago - with room for new lanes without changing the major structures.

KevR · 21-11-2014 5:08pm

Feed Up wrote: »

Thanks for the reply L1011.

Have I got this right? If I'm traveling on the M6 W and want to get onto M18 S I will have to go through a roundabout controlled by lights.

So the only benefit from this layout is that if someone overshot the exit prior to the M6/M18 interchange they can turn here instead of going to the next exit.

If they built a free flowing interchange the person above would be no worse off than they are today if they overshot the exit.

Why can't the NRA do proper free flowing junctions, particularly for motorway interchanges?

I though we would have learned the lesson about motorways, roundabouts and traffic lights at this stage.

Not to mention, well in my opinion for what it's worth, that the interchange as described by L1011 will look great to any of our European neighbours - motorway interchanges controlled by lights when they've had free flowing for decades.

L1011 wrote: »

Yes, that's right. And yes, its a terrible junction design.

It was done so they could put a service station on it - but the service station was refused planning and now we're stuck with it!

However, its a pretty common interchange type internationally on quieter motorways which this will be, mind.

There will be free-flow left turn lanes. Only traffic making a right turn or a u-turn will go through the roundabout. That being said, it's terrible junction design.

For example:

M6 West to M18 South will avoid the roundabout and be free-flow.
M6 West to M18 North will go through the roundabout and not be free-flow.

Interactive maps:

Feed Up · 21-11-2014 6:20pm

Hi KevR,

Thanks for the info.

One half of me, the cynic half, would say they have it half right.

The other half, the well and truly cheesed off half, from all the hours wasted by the bad road design of the late 80s and 90s, would be firmly of the view that it should be free flowing, period.

I can't understand the logic of linking two roads with vehicle speeds of 120kph with what is in effect a stop/go system. Where are the H&S people when you want them? How can the NRA justify stopping fast moving traffic, for what 45/60 seconds, so as to save a few million euro on construction and land costs?

I remain to be convinced that the proposed 'half roundabout system' will be cheaper than running one motorway over the other and putting an on-ramp and an off-ramp in each of the four corners.

The plans were there to build the M18 when the M6 was being built so I wonder was the M6 future proofed for linking to the M18 so as to avoid months upon months of cones/bollards, speed restrictions, lane closures, etc etc when they are being joined up. Someone please tell me they have.

Goofy · 21-11-2014 7:01pm

Feed Up wrote: »

Hi KevR,

Thanks for the info.

One half of me, the cynic half, would say they have it half right.

The other half, the well and truly cheesed off half, from all the hours wasted by the bad road design of the late 80s and 90s, would be firmly of the view that it should be free flowing, period.

I can't understand the logic of linking two roads with vehicle speeds of 120kph with what is in effect a stop/go system. Where are the H&S people when you want them? How can the NRA justify stopping fast moving traffic, for what 45/60 seconds, so as to save a few million euro on construction and land costs?

I remain to be convinced that the proposed 'half roundabout system' will be cheaper than running one motorway over the other and putting an on-ramp and an off-ramp in each of the four corners.

The plans were there to build the M18 when the M6 was being built so I wonder was the M6 future proofed for linking to the M18 so as to avoid months upon months of cones/bollards, speed restrictions, lane closures, etc etc when they are being joined up. Someone please tell me they have.

There is no H&S issue. The merge and demerge lanes will be plenty long enough to allow safe acceleration and deceleration. The same as as any other junction. I think adding 60 seconds to an average hour long journey to save millions of euro is more than acceptable. In fact I would strongly encourage it.

It's not just putting an on ramp and off ramp on four corners. It's buying a lot more land. It's cost and time of designing a much more complicated road layout. It's the cost and time in building a more complex design. It's more bridges. It's more complicated sweeping bridge design............. It's a lot more expensive.

The hard shoulders on the M6 at the junction location are extremely wide in anticipation of the tie in with the new road. There will be some disruption but that's inevitable.

Middle Man · 21-11-2014 7:08pm

That said interchange proposal is not great but I seriously doubt it will be any major issue for at least a couple of decades. We just need the motorway like now. Then there's the m20...

KevR · 21-11-2014 7:13pm

Goofy wrote: »

I think adding 60 seconds to an average hour long journey to save millions of euro is more than acceptable. In fact I would strongly encourage it.

It's not just putting an on ramp and off ramp on four corners. It's buying a lot more land. It's cost and time of designing a much more complicated road layout. It's the cost and time in building a more complex design. It's more bridges. It's more complicated sweeping bridge design............. It's a lot more expensive.

Where is the evidence to suggest that full free-flow is more expensive than a 3-level stack? Many people in this thread are of the opinion that there is very little in cost difference. Some even think that the 3-level stack might be more expensive!

My belief is that the 3-level stacked roundabout was chosen because the NRA wanted to attach a Service Area onto the roundabout (easy to serve both the M17/18 and M6 with a single service area via a roundabout. Unrealistic to serve both routes with a single service area via a full free-flow).

Planning permission for the Service Area has been denied. Unfortunately, we are appear to be stuck with this out-dated junction design.

L1011 · 21-11-2014 7:20pm

Goofy wrote: »

It's not just putting an on ramp and off ramp on four corners. It's buying a lot more land. It's cost and time of designing a much more complicated road layout. It's the cost and time in building a more complex design. It's more bridges. It's more complicated sweeping bridge design............. It's a lot more expensive.

In most cases, a triple level stack uses - and wastes, as its unusable islands - more land than most modern equivalent interchanges.

The construction costs wouldn't be much higher as a new build either

The ONLY reason this was picked was to allow them to put the service station on it, which isn't happening.

csd · 21-11-2014 8:11pm

L1011 wrote: »

The ONLY reason this was picked was to allow them to put the service station on it, which isn't happening.

I've heard the NRA will be re-submitting planning permission for an MSA at this location.

/csd

Chris_5339762 · 21-11-2014 8:42pm

Feed Up wrote: »

Hi KevR,

The plans were there to build the M18 when the M6 was being built so I wonder was the M6 future proofed for linking to the M18 so as to avoid months upon months of cones/bollards, speed restrictions, lane closures, etc etc when they are being joined up. Someone please tell me they have.

Yes. M6 is wider at the junction location... but I guess there will be a few closures as they drop bridges in.

The nerds among you will also notice that all the bridges and median are wide enough between the M6/17/18 junction and Galway to take D3.

busyatwork · 23-11-2014 3:29pm

Only time will tell how the junction will work, if they get the rest of the road constructed,it will only be a minor issue out of a great road network .

AugustusMinimus · 23-11-2014 6:21pm

Goofy wrote: »

It's not the best design, but it's definitely much cheaper. I think it's safe to say that this junction won't see red cow levels of traffic in my lifetime. Why waste money on a free flow junction when its never going to be required?

Could you please back up your assertion that a 3 level stack is cheaper than a partially unrolled cloverleaf or the like.

Comparing both the designs (M20-M40 junction for instance) it looks to me that the current M6/M17/M18 is much more complex, will require a lot more earth works and in the end, will be much less efficient.

This is what is wrong in this country. Nothing can be done right originally. Every single car going from Tuam to Galway will have to access the roundabout. This is absolute madness and I will not back down in this assertion as I have done so already numerous times in this thread.

M6/M17/M18 junction

M20/M40 junction

You might let me know why the 3 level stack will be cheaper.

AugustusMinimus · 23-11-2014 6:25pm

Goofy wrote: »

There is no H&S issue. The merge and demerge lanes will be plenty long enough to allow safe acceleration and deceleration. The same as as any other junction. I think adding 60 seconds to an average hour long journey to save millions of euro is more than acceptable. In fact I would strongly encourage it.

It's not just putting an on ramp and off ramp on four corners. It's buying a lot more land. It's cost and time of designing a much more complicated road layout. It's the cost and time in building a more complex design. It's more bridges. It's more complicated sweeping bridge design............. It's a lot more expensive.

The hard shoulders on the M6 at the junction location are extremely wide in anticipation of the tie in with the new road. There will be some disruption but that's inevitable.

Please back up your assertions that

1. You would have to buy a lot more land
2. It is a much more complicated design
3. Its more bridges (in fact, my design shown above would involve less bridges)
4. It would be a lot more expensive.

It appears to me that the assertions you are making in this thread are nothing more than guess work, or worse.

Feed Up · 24-11-2014 12:07pm

Ok, my reference to H & S was probably a bit OTT.

My view is that I can't see the logic in putting a stop/go system on what should be effectively be a continuous 120kpm road. Transferring from one motorway to another should be seamless.

I do accept that putting in a MSA requires access from the motorways and the other roads. But there must be similar junctions/interchanges in the UK and on the continent that solve this problem without resorting to roundabouts and traffic lights.

spacetweek · 24-11-2014 1:49pm

AugustusMinimus wrote: »

Comparing both the designs (M20-M40 junction for instance) it looks to me that the current M6/M17/M18 is much more complex, will require a lot more earth works and in the end, will be much less efficient.

Every single car going from Tuam to Galway will have to access the roundabout.

The proposed M20/M40 junction will be right next to an urban area and will need to handle far more traffic.
Tuam is a town of 3,000 people. The busiest movement in the 6/17/18 junction will probably be M6 Galway->M18 and vice versa. This would only require one freeflow slip to be built, should we ever need it.

M17/M18 - Gort to Tuam [open to traffic]

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