Freeflowing interchanges

Andrew Duffy

Anyone know of any real motorway/dual-carriageway interchanges in the Republic? Here's a good list of the various types. The only one I know of is this trumpet:



...which was described as being on the N22 in the PDF i took it from, but which I think may be the interchange between the N20 and N21 near Patrickswell.

Seth Brundle

How could Ireland have real motorway interchanges if we don't have real motorways?
The Irish policy of integrating roads seems to be aimed for crap drivers - we have to slow down to 50mph @ the jusntion of the M50 & M1 for example.

gurramok

...and put roundabouts at the interchanges and for good fun put traffic lights there as well. Flyovers are rare here

Victor

The only true motorway / motorway junction (where no one, ever, has to stop) is the M7/M9 at Kilcullen / Newbridge / Kildare, but even that is incomplete (no left turn from M9 northbound to M7 westbound, diversion through Kilcullen or reverse). Some of the exits (e.g. Gormanstown) on the M1 where old M1 bypasses are joined up will have motorway characteristics.

Most of the M50 junctions were designed as Three-Level Stacked Roundabouts, but were left incomplete. Currently several are Three-Level Stacked Roundabouts with Diamonds. It is proposed to turn several into Three-Level Stacks or variants of Three-Level Stacked Roundabouts.

The Bloomfield interchange in Cork is a Trumpet type, but not on a motorway and has speed limitations, as is the first junction (from Dublin) on the M7 at Naas (at end of motorway).

Andrew Duffy

Don't two of the sliproads cross at grade in the junction at Naas? At least that motorway was built back in the days when some of the required aspects of motorway design were taken seriously.

I'm pretty sure the Gormantown interchange is a diamond, or a diamond with roundabouts. Didn't know about the one in Cork, so thanks for that.

The junction between the M50 and M11 will be the same kind of restricted spur junction as M7/M9. Oddly, the straight through path will be M50 and you'll have to turn off to stay on the M11. The other movements will be catered for by yet another diamond with roundabouts on the M50 and a link road to the (freeflowing? can't tell) Wyatville interchange on the N11.

jd

Originally posted by Andrew Duffy
Oddly, the straight through path will be M50 and you'll have to turn off to stay on the M11.

That actually seems sensible enough to me.

loyatemu

(freeflowing? can't tell) Wyatville interchange on the N11.

definitely not freeflowing - it is now open and is covered with traffic lights

Victor

Originally posted by Andrew Duffy
The junction between the M50 and M11 will be the same kind of restricted spur junction as M7/M9. Oddly, the straight through path will be M50 and you'll have to turn off to stay on the M11. The other movements will be catered for by yet another diamond with roundabouts on the M50 and a link road to the (freeflowing? can't tell) Wyatville interchange on the N11.

The M50 will stop at Sandyford - the South Eastern Motorway (through Carrickmines) will be M11. People are just being simplistic and lazy (and in part serving their own agenda) in calling it the M50.

Andrew Duffy

...people including the NRA! They also describe the Port Tunnel as being part of the M50, when it can't be anything except M1, at least not without rebuilding the interchange.
Does anyone know if the stretch of M1 that was dug up to build the port tunnel will be reinstated? If so, will it be a motorway spur that runs directly above the motorway it's a spur of? That would be interesting.

Victor

Originally posted by Andrew Duffy
...people including the NRA! They also describe the Port Tunnel as being part of the M50, when it can't be anything except M1, at least not without rebuilding the interchange.

Because it is. The M50 is the Dublin Ring Road. See recent thread on Commuting / Transport about the Eastern Bypass

NeRb666

Originally posted by Andrew Duffy

Does anyone know if the stretch of M1 that was dug up to build the port tunnel will be reinstated? If so, will it be a motorway spur that runs directly above the motorway it's a spur of? That would be interesting.

It's going to be left as a single lane road once the tunnel opens. Also, there are no plans to upgrade the M50/M1/N32 interchange to deal with the increase in traffic that will happen when the tunnel is opened.

Andrew Duffy

There are plans to upgrade the M50-M1-N32 interchange, along with the M50-N4 and M50-N7 ones and the construction of an extra lane along most of the M50. The M1 interchange has to be rebuilt to send the M50 straight through, since the Port Tunnel is part of it, despite appearances to the contrary. It won't be easy; the two motorways meet at a very sharp angle, and there is an industrial estate right in the apex of it.

Victor

Actually it shouldn't be too difficult there is plenty of free land available. There might actually be an advanage in retaining the roundabout as the end of the M/N32 as it would give drivers coming east on the M50 a reality check that they are at the end of the motorway.