Motorways

prendy · 26-10-2007 10:55am #1

Can someone please exlpain the difference between a dual carrige way and a motor way.the N4-N6 road changes from a motorway to a dual carriageway with no real change in road structure...just wondering why this is?

r3nu4l · 26-10-2007 11:16am

prendy wrote: »

Can someone please exlpain the difference between a dual carrige way and a motor way.the N4-N6 road changes from a motorway to a dual carriageway with no real change in road structure...just wondering why this is?

I'm not entirely sure but afaik, a Motorway has proper exit and entry ramps and no traffic lights whereas a dual carriageway can have traffic lights and entrances that are like crossroads rather than entrance/exit ramps.

I'm sure someone will post some much more detailed 'official' documentation

but that's my take

steve-o · 26-10-2007 11:29am

The roads authority plan to re-classify lots of those dual carriageways (like the N6) as motorway. I think the reason they are first built as dual carriageway and then re-classified later on is some stupid legal reason (maybe to do with planning laws). It has been in the news several times, and there have been several threads here discussing the proposed changes, including how daft it is that there are dual carriageways with 120kmh speed limits without the safety restrictions that a motorway would have.

prendy · 26-10-2007 11:32am

thanks for your replies...its just that section of N6 is the same as the motorway it merges with...proper on-off ramps etc.i suppose it'l be reclassified.just annoying driving at 100 on a road like that!

Mitch Connor · 26-10-2007 11:40am

Some of them can't be classed as motorways because of the geographic position. Some high quality roads are built through land that was bought from farmers, and a condition of sale of some of these sites was that the road would not be classified as motorway, but as a national road so that tractors would still be legally allowed to drive on them, from field to field.

That is what i have been told in the past anyway.

Chris_533976 · 26-10-2007 12:46pm

As it stands, the High Quality Dual Carriageways (HQDCs) are build to the same standard as motorways. But up to a few months ago, a road could only be classified as a motorway if it was built as such.

Long story (and generalising a lot), the farmers complained about motorways because they couldnt take the tractors on them. So the roads were (and are being) built as motorway-standard HQDC and given N classification and 100kmh speed limits.

Fast forward to this summer, you have the Roads Bill 2007, which allows the simple reclassification of these HQDCs to motorways. Problem hopefully solved, and the main interurbans N 6,7,8,9 are going to be M soon

icdg · 26-10-2007 6:38pm

Basically the difference is this:

A dual carraigeway is a road type. It means that traffic travelling in different directions are physically seperated by a barrier or median. (Yes, even a 2+1 road is technically a dual carriageway).

A motorway is a classification and a set of rules which are applied to a road. It at its basics means means that only motor vehicles capable of doing at least 50 km/h are allowed to use it. No pedestrians, animals, pedal-cyclists etc. At its full standard, it is a dual carriageway with no private accesses, no access points except for fully grade seperated interchanges, with at least two lanes in each direction and a hard shoulder, a design speed of 120kph, and an alternative route available for traffic unable to use the motorway. But note that some motorways are of less than the full standard (for example, M50 Southern Cross has a speed limit of 100 km/h). This does not stop them being motorways as the restriction to motor traffic is the defining feature.

In Ireland, we've traditionally created motorways by using a process known as a Motorway Scheme which is proposed by a road authority, and after a public inquiry signed off on by the Minister. The road is then built with the necessary regulations from opening date (and is normally declared a national road also). This differs from dual carriageways which are applied for using the normal planning process.

In Ireland, we've appropiated the term "high quality dual carriageway" to describe a road built to the **standard** of a motorway, but without the **restrictions** that go with it. The restrictions can be implemented by means of an order under the Roads Act 2007 which makes the HQDC a motorway, as if it had been built under a Motorway Scheme.

Hotblack Desiato · 26-10-2007 9:36pm

icdg wrote: »

But note that some motorways are of less than the full standard

Here's a single carriageway motorway :eek:

corktina · 26-10-2007 9:50pm

there is nothing to stop the speed limit on a HQDC (and other roads) being increased to 120...why are they so slow in doing this?

fricatus · 26-10-2007 11:01pm

Chris_533976 wrote: »

Long story (and generalising a lot), the farmers complained about motorways because they couldnt take the tractors on them. So the roads were (and are being) built as motorway-standard HQDC and given N classification and 100kmh speed limits.

(Adopts Victor Meldrew tone) I don't believe it!

FFS, I mean come on... it is so dangerous to have tractors on such fast roads. Typical capitulation of this government to the farmers. They should have told them where to stick their bloody tractors, and at the same time ban them from national roads at morning and evening peak times.

Chris_533976 wrote: »

Fast forward to this summer, you have the Roads Bill 2007, which allows the simple reclassification of these HQDCs to motorways. Problem hopefully solved, and the main interurbans N 6,7,8,9 are going to be M soon

Problem hopefully solved indeed, and if I see any of them on the M9 when it's built, I swear to God, I'll call it into the local cop shop.

corktina · 26-10-2007 11:24pm

yesterday...Kinsale Rd flyover...three lanes....tractor crawling over flyover with muck spreader or something behind it......MIDDLE LANE!!!!

E92 · 26-10-2007 11:43pm

corktina wrote: »

there is nothing to stop the speed limit on a HQDC (and other roads) being increased to 120...why are they so slow in doing this?

Well after Cork County Council's attempts to try to increase them and look where they got, perhaps nobody has decided to bother since?

Apart from the N1 and N2 bits, they're not Motorway, and they have a120 km/h limit.

Chris_533976 · 27-10-2007 12:47pm

Those plans of Cork Co Council were not allowed because it was before the Roads Bill went through. What they wanted to do was increase the speed limit to 120kmh without motorway restrictions, which was daft and dangerous, as the road in question (n25) carries a LOT of tractors, cyclists and people walking.

E92 · 27-10-2007 3:54pm

Chris_533976 wrote: »

Those plans of Cork Co Council were not allowed because it was before the Roads Bill went through. What they wanted to do was increase the speed limit to 120kmh without motorway restrictions, which was daft and dangerous, as the road in question (n25) carries a LOT of tractors, cyclists and people walking.

But ever since they changed the speed limits to kilometres, it has been possible to have aspeeed limit higher/lower than the "default" limit.

And while what your saying explains what happened with the N25, what about the N8 then? They wanted to change the Motorway standard bits to 120 as well.

Anyway a DC(M-way or not) is a much safer road than a Single Carriageway so therefore is deserving of a much higher speed limit.

Chris_533976 · 27-10-2007 5:18pm

Personally I really dont agree with 120kmh without Motorway restrictions. Coming up on an idiotic cyclist at a sliproad at 120kmh is an accident waiting to happen.

I think they said no to this because they knew the Roads Bill would allow them to do it properly anyway.

27-10-2007 5:41pm

Chris_533976 wrote: »

Personally I really dont agree with 120kmh without Motorway restrictions. Coming up on an idiotic cyclist at a sliproad at 120kmh is an accident waiting to happen.

I think they said no to this because they knew the Roads Bill would allow them to do it properly anyway.

Coming up to a cyclist on a slip road at any speed is dangerous unless the sliproad has a cycle crossing point and cyclists use it.

A bit like this

E92 · 27-10-2007 6:47pm

Well I agree it is better to have Motorway restrictions and then have the 120 limit(which is still slow enough but nevertheless a big improvement on 100), but since they have been talking about upgrading these roads to M-way for so long now and nothing has been done that I'd rather see the introduction of 120 and no restrictions than leave things be.

They are still a lot safer with or without M-way restrictions no matter what and therefore we should be allowed to drive faster on them.

I think 120 is about right for a HQDC(well really I don't but since the Irish can't drive properly 120 is about as much as you could get away with in this country), and 130/140 should be the Motorway speed limit.

100 and 80 are fine really for the single carriageways, the problem there is that some are 80 when they should be 100 and vice versa, and of course my pet hate the 60 km/h limit(which should be 70).

Irish and Proud · 27-10-2007 7:49pm

Tauren wrote: »

Some of them can't be classed as motorways because of the geographic position. Some high quality roads are built through land that was bought from farmers, and a condition of sale of some of these sites was that the road would not be classified as motorway, but as a national road so that tractors would still be legally allowed to drive on them, from field to field.

That is what i have been told in the past anyway.

Most National Primary road projects are controlled roads whether they are S2, D2AP, D2HQ or D2M. My understanding is that for safety reasons, access for any motor vehicle is limited to specific junctions whether they are GSJs or AGJs. The only exceptions would be online or retro-fit schemes, but even so, farm accommodation bridges or underpasses are usually provided and that is where the farmers are meant to go - and especially with the IR£20K/acre (based on the year 2000) price tag that we as tax payers are forced to pay, so if they want to roam across main highways, I suggest they go to some other country which might be happy to oblige! :rolleyes:

Motorways

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