First roads to be declared motorways without a motorway order

icdg

icdg wrote: »

Athlone-Galway is the major part of the inter-urban network left out, possibly due to the Athlone Bypass needing major work before it can be redesignated.

The other reason for this remaining as an "N" road for the foreseeable future is that the town council would be reluctant to have all the tractors etc going through the town.

There are plans for a southern link road running from (near) Kilmartin roundabout to the old Tuam Road junction near Elan, when (if) this is completed then the whole N6 can be motorway.

Victor

Victor wrote: »

Athlone bypass - I think some of the junctions are really tight - the Ballymahon Road and Coosan Point Road junctions are very close together.

No real problem here as there is a third lane between them (like the new M50).
A couple of the bends are a bit tight for 120Kmh imho, after driving along the new sections of the N4 it's realy noticable just how tight they are!

uberwolf

E92 wrote: »

No because we have loads of HQDCs slapped with a limit of only 100 km/h(only the road to the border and the Finglas Bypass have a limit of 120).
When the M50 gets upgraded it will have a limit all around it of only 100 km/h. And if you read my post you would realise that I said Motorway standard roads i.e. HQDC and obviously Motorways.

HQDCs have a design speed of 120 km/h.

Can someone please define what the "design speed" refers to, for example, an F1 racing car would have no problems handling any of these roads at speeds in excess lf 250Kmh.

Is it the maximum speed a "typical" road car can drive without losing control? or the max speed for the same car to drive without the driver having to "work" the car?

There are many different figures being bounded about here.

E92

Victor wrote: »

Are the (other) vehicles designed to 160km/h and and the drivers trained to drive at such speeds?

Well they've managed fine all those years in Germany, with different vehicles being designed for different speeds. I therefore presume they would. Most cars have a top speed well in excess of 160 km/h these days, so I've no doubt about the cars' ability to cope.

As for the drivers, well that of course is a completely different story:D.

Needless to say you couldn't have a speed limit of 160 km/h now, the country's ledgendary driving ability would certainly not be able for 160 km/h at the moment(about 140 is the height of what could be done at the moment IMO) but if we all drove properly, then I don't see any safety issue with it(points to Germany where they actually do drive properly and plenty of people drive well in excess of 160 km/h when given the opportunity).

And as people constantly say it's a limit and not a target, so if you don't want to go that fast, then you don't have to.

uberwolf

Deleted User wrote: »

Can someone please define what the "design speed" refers to, for example, an F1 racing car would have no problems handling any of these roads at speeds in excess lf 250Kmh.

Is it the maximum speed a "typical" road car can drive without losing control? or the max speed for the same car to drive without the driver having to "work" the car?

Design speed is the what they consider when they're figuring out what the maximum permissable curvatures are
because you need to always allow stopping sight distance - people need to be able to stop within the distance that they can see to be clear ahead of them
and obviously that length goes up the faster you're going
junction design is also based on design speed, width of lanes (though that's pretty standard at 3.5m now)
basically it's how fast they built the road to be driven on safely
(safety defined as meeting the current standards)

mackerski

Victor wrote: »

Are the (other) vehicles designed to 160km/h

Yes, with rare exceptions. Many would have issues at, say, 200km/h (some just can't reach it, others can, but wouldn't have brakes appropriate to that speed). Most modern tyres would cope with 200-220km/h without difficulty.

Victor wrote: »

and and the drivers trained to drive at such speeds?

I can't imagine that many learner drivers are "trained" for speeds much in excess of 80km/h, which is as fast as most people will drive on test. Yet we allow their gained experience to condition them to drive at 120. Incremental increases beyond 120 on a motorway don't represent vast changes in the observation and driving styles required. And the primary rule remains unaltered: drive no faster than is safe under the prevailing conditions and be sure that you can safely stop at any time.

Victor

E92 wrote: »

Well they've managed fine all those years in Germany, with different vehicles being designed for different speeds. I therefore presume they would. Most cars have a top speed well in excess of 160 km/h these days, so I've no doubt about the cars' ability to cope.

Are you saying that a typical car, involved in an incident at 160km/h on a motorway, won't have fatalities?

mysterious

I drove on the Nenagh bypass the other day at night, and was amazed to see the scale of excavation taking place on either side of the S2 road now, even at 9pm they were working. They are seriously cracking on this end now.

It appears to me that it will be a motorway with HS rather than the narrow 4 lane road with hard strips stated in the old EIS. i.e Standard DC.

Also two of the overbridges are just too tight for me to see a four lane motorway squeezing through.


P.S Does anyone know what is planned with the narrow bridges? are they being knocked or modified or widened how??

Zoney

mysterious:

I'm guessing no hard shoulders under the bridges, not unheard of on motorways e.g. in UK. Also the median will probably not be much wider than a New Jersey barrier.

The upgrade of this road so soon after it opened the first time seems amazing to some, but it's not hard to understand at all when you consider it was planned nearly 20 years ago, and even ten years ago the intention wasn't there to have motorway/DC all the way to Dublin. The traffic volumes along the Nenagh bypass are very low, well below even 2+1 recommended capacity (incidentally the same goes even for the N8 north of Cashel, the N9 south of the N10, the N6 west of Athlone). As such, the motorway is only needed under the more recent considerations of providing safe and fast travel between the major urban centres irrespective of traffic volume.

MDTyKe

uberwolf wrote: »

HQDCs have a design speed of 120 km/h.

Grossly incorrect - their design speed is exactly the same as motorways. If it was 120, the max speed limit would be around 90-100 to allow for people slightly breaking the limit and to stop them flying off the corners...


Matt

Niall1234

Victor wrote: »

Are you saying that a typical car, involved in an incident at 160km/h on a motorway, won't have fatalities?

Any idea what the stats from Germany say on this point ?

Lennoxschips

Yep, Germany and the Netherlands have motorways of similar quality, yet the Netherlands with its very strictly enforced 100 and 120 limits has the lowest fatality rate in Europe. Germany lags well behind.

Here All the countries listed above Germany in this list are well known for their affection for speed cameras and speed limits.

All we need is the eco-mentalists to object because some fool thinks that 120 km/h is so much worse for the environment(apparently a car uses 10% more fuel at 120 than at 100, though I doubt it very much, since modern cars would be well designed to be at their optimum efficiency at 120-130 km/h, the general speed limit on most European Motorways),

You doubt it very much? If your car has an on board computer you should test it out. This is what I get (in a modern Diesel estate):

Doing 140/150 km/hr on the Autobhan: 6.5 litres per 100 km.
Doing 120 km/hr on the Dutch motorways: 5.4 litres per 100 km.
Doing 100 km/hr on the Dutch motorways: 4.6 litres per 100 km.
Doing 80 km/hr on the Dutch motorways: 3.5 litres per 100 km.

This difference in consumption is pretty consistent with the published data on almost all models of cars.

A motor vehicle's optimum efficiency is at 80 km/hr. 80 km/hr uses some 40% less fuel per km travelled than 120 km/hr. 100 km/hr is in between.

But don't let the facts get in the way of a good rant against "eco-mentalists".

Chris_533976

Lets not forget that some Dutch motorways have an AADT of 100,000 on 2x2 lanes. Of course they're safe, cos you're in 20+km traffic jams.

Lennoxschips

Germany is well known for big long traffic jams. A lot of accidents happen when a traffic jam suddenly occurs and the very fast moving traffic rear ends the cars in front.

Have a look at that link, Germany ranks below a lot of countries in terms of road safety. Those are the hard facts.

Variable speed limits reduce this type of accident.

The M25 in the UK makes good use of this technology by progressivly dropping the limit in the couple of miles before the queue.

mysterious

Zoney wrote: »

mysterious:

I'm guessing no hard shoulders under the bridges, not unheard of on motorways e.g. in UK. Also the median will probably not be much wider than a New Jersey barrier.

The upgrade of this road so soon after it opened the first time seems amazing to some, but it's not hard to understand at all when you consider it was planned nearly 20 years ago, and even ten years ago the intention wasn't there to have motorway/DC all the way to Dublin. The traffic volumes along the Nenagh bypass are very low, well below even 2+1 recommended capacity (incidentally the same goes even for the N8 north of Cashel, the N9 south of the N10, the N6 west of Athlone). As such, the motorway is only needed under the more recent considerations of providing safe and fast travel between the major urban centres irrespective of traffic volume.

Well it does seem it will be a full blown 2x2 motorway with HS on it's total lenght.
The Dolla and Limerick(n52) bridges needs to be knocked, regardless if they are not putting a hard shoulder in it. It is sickening to imagine that they only built this in less than a decade and now they are widening it.

When the bypass was first proposed,

It was meant to a be motorway or DC. The Tipperary council built the first two bridges to small and the latter of the plan just kept it S2 when the main contractors were signed. Coffey constructin if I remember correctly. The contractors also forgot incoporate the Thurles interchange. They thought no one would notice, or thereabouts. I got all this info from a guy who was working on the bypass at the time.:)

Bear in mind they were already planning a toll motorway from Nenagh to Limerick, and they just go build a 9km stretch S2 with motorway charistictics, and they now have to make it motorway properly as with the latter of the route.


The Dublin end road arch bridge that is incoporated into the Castletown M7 scheme(due to start now) will have to be knocked, period.

P.S Nenagh bypass is part of the reclassification of motorway as of most of the inter urban sections HQDC. Though the Nenagh bypass is been built as a standard DC but of course it will be dotted with blue signs??

I'm really shaking my head... REALLY... i just don't see the point inrebuilding something half right, never mind getting the planning wrong the first time wrong.

murphaph

Deleted User wrote: »

Variable speed limits reduce this type of accident.

The M25 in the UK makes good use of this technology by progressivly dropping the limit in the couple of miles before the queue.

A good point. Germany is rolling out a lot of variable speed limit signs these days too.

Metrobest

Lennoxschips wrote: »

A motor vehicle's optimum efficiency is at 80 km/hr. 80 km/hr uses some 40% less fuel per km travelled than 120 km/hr. 100 km/hr is in between.

But don't let the facts get in the way of a good rant against "eco-mentalists".

Setting the speed limit has to find a balance between safety, ease of mobility and regard for the environment.

Recently, all motorways in the greater Barcelona area have had their speed limits slashed to 80kmph (they were 120kmph) on 3x3 lane motorways. Overhead digital displays every few hundred metres warm drivers of speed cameras set up to detect those doing more than 80.

The policy seems to have worked - in terms of drivers respecting the limits. However it does seem a little senseless to restict speed in the metropolitan area because as soon as you pass the 80km cordon drivers are right back up to 120. I understand why. It feels very slow doing 80 on a wide motorway.

Additionally, the policy adds 20 minutes per day to the journey times of drivers coming into Barcelona to work, so that means extra stress, hassle and less quality time for people in their lives. Have we become so fixated on the global warming issue that we cannot see how dogmatic policies have an even nastier impact on human happiness?

When the pollution stastics come out in in few months, more will be known about whether or not this 80kmph policy can be justified.

murphaph

mysterious wrote: »

Also two of the overbridges are just too tight for me to see a four lane motorway squeezing through.


P.S Does anyone know what is planned with the narrow bridges? are they being knocked or modified or widened how??

Anything's possible .....

Lennoxschips

Additionally, the policy adds 20 minutes per day to the journey times of drivers coming into Barcelona to work, so that means extra stress, hassle and less quality time for people in their lives. Have we become so fixated on the global warming issue that we cannot see how dogmatic policies have an even nastier impact on human happiness?

Those long commutes are due to the terrible recent urban planning in Spain, not speed limits.

They do the same thing with speed limits in Amsterdam and Paris.

Reduced fuel consumption (up to 40% reduction at 80 km/hr) of course reduces emissions, not only of greenhouse gases, but also sooty particles. Sooty emissions in urban areas are a major problem and that's why urban areas have decided to enforce these limits, thus promoting cleaner air in the cities, better human health, ultimately better human happiness... Seeing as nearly all cars don't have emissions filters on them, this is a good measure.

fricatus

murphaph wrote: »

Anything's possible .....

H0ly sh1t! Where's that, murphaph?

murphaph

fricatus wrote: »

H0ly sh1t! Where's that, murphaph?

Here, on the A4 north of Chemnitz, Germany.

1huge1

wow theres something you dont see every day

I thought it was a photoshop!

Just shows what can be done!

Victor

mysterious wrote: »

The contractors also forgot incoporate the Thurles interchange. They thought no one would notice, or thereabouts. I got all this info from a guy who was working on the bypass at the time.:)

You need to learn when people are telling you stories. Contractors don't decide stuff like this.

What Vision?

The design speed is 120 km/h for motorways, well that's what the manula say. What Factor of Safety theyare using, well that's anyones guess, 1.25 (150 km/h) , 1.5 (180 km/h), 2.0 (240 km/h).

Remeber when you are on a motorway, not all the corners are to the minimum. If you drove on a minimum corner for a 120 km/h design speed, well then you'll know if 120 km/h is the actual design speed or not.

Like the M50 Southern Cross Motorway, that has a 100 km/h speed limit, and if you do 120 km/h on it, it can be a bit tight. So it's done to less than the minimum for a 120 km/h speed limit.

Minimum Radius for a road is
120 km/h => 2040 m
100 km/h => 1440 m
80 km/h => 1020 m (actually 85 km/h in book)
60 km/h => 510 m
50 km/h => 360 m

mysterious

Victor wrote: »

You need to learn when people are telling you stories. Contractors don't decide stuff like this.

Your right. But this is Ireland though... Even when it was first opened it was publicly announced "was out of date"

The Thurles interchange was in fact left out, the contractor is told to build whatever, so the planners or county council fuked up on it. they probably ran out of money.

The bypass over 8miles long and there is no access in the middle for the heavy mid Tipp traffic to acces the N7 onto limerick etc. The R498 is a busy regional road. NRA are not making the same mistake leaving it out after the upgrade.

Zoney

mysterious:

The fact is that the original Nenagh bypass was designed in a different era as far as attitudes and funding towards road construction in Ireland are concerned. Anyone who bemoans the fact of it not having been DC from the start is simply ignoring how reality was even just 10 years ago, nevermind when the road plan for the 1980s was published (1979) which included most of the bypasses we built late 80s/early 90s (or even later).

Nevermind that the attitude ignores the quite reasonable fact of simply consider traffic volume, present and future, at the part of the N7, which are low.

The only reason for DC/motorway is the strategic concern of complete interurban motorways, which is a relatively recent ambition.

The missing Thurles juncton, while silly, is not surprising as a cost-cutting measure in the original construction, and was not some kind of disaster. In the scale of things the traffic involved is not a lot.

mysterious

Zoney wrote: »

mysterious:



Nevermind that the attitude ignores the quite reasonable fact of simply consider traffic volume, present and future, at the part of the N7, which are low.

The only reason for DC/motorway is the strategic concern of complete interurban motorways, which is a relatively recent ambition.

The missing Thurles juncton, while silly, is not surprising as a cost-cutting measure in the original construction, and was not some kind of disaster. In the scale of things the traffic involved is not a lot.

Well i was talking to a guy who was working on this road. They were planning a motorway from Limerick to Nenagh already when the bypass was under construction. The reason it was not DC here, cus the Tipperary council built the first two bridges to narrow, and coffey then got the contract to build after. one of the other bridges is in fact wide enough for 4 lanes. It was very stupid to build a a single lane road that lenght with flyovers.

I hate to burst your bubble, but they were many bypasses built around this time and before that were built to motorway standard

1.Arklow bypass
2.Athlone bypass
3.Mullingar bypass all built before the Nenagh bypass.

The low traffic flows is partly because of the missing interchange. Local traffic cannot access the road. even still they should of left space for future proof.