Why was the standard of motorways downgraded?

dublincc2

If you look at the first batch of motorways to be built in the Republic (M1, M4 to Kinnegad, M7 to Portlaoise, M9 Kilcullen etc) they have wider lanes and better quality medians (with a grass strip and trees) that from what I believe are in case a third lane needs to be added. The newer interurban motorways that FF built in the late 90s/00s (redesignated HQDCs) have narrower lanes and a concrete median.

Was there a specific reason why they decided to reduce the standards of the motorways in this way? Was it concerns about land take? Because they were technically built as HQDC and not motorway?

blackbox

I believe the first ones were built to British standards and the later ones to European standard.

dublincc2

https://www.boards.ie/discussion/comment/123657680#Comment_123657680

I think the motorways in the North are 3.50m as well, compared to 3.75m in GB.

L1011

Costs.

Reduced land take adds up a lot. Less concrete and steel for structures, again adds up with the number of structures involved - there's a lot of culverts you never notice for instance.

PixelCrafter

There was also research showing a solid median did a lot more than the big wide open grass medians the original motorways had. They had no central barrier at all in the first designs.

The early British spec also assumed 1960s poor handling, bad steering and no speed limits.

alias no.9

A lot of the newer ones carry lower volumes of traffic and were built and opened as HQDC but later redesignated as motorways. They are unlikely to max out on capacity so don't need the extra land reservation for a third lane.

con747

https://www.boards.ie/discussion/2058420130/why-was-the-standard-of-motorways-downgraded

So you reckon the  M4 to Kinnegad was built pre late 1990's? How the hell did I miss that going home everyday on the old road.

JVince

https://www.boards.ie/discussion/comment/123657854#Comment_123657854

Feck - same here. Was sitting in tailbacks in Kildare town in late 90's and through to 2003 when there was a motorway available that no-one knew of?

Larbre34

There is no reduction in standards.

In point of fact, motorways with deflective concrete median barriers are far safer at keeping vehicles involved in collisions on their own carriageway and dissipating energy from a crash.

With the early motorways, there was only a wide grass median. A vehicle could very easily cross the median and become involved in a head on collision.

This did happen, and so cable arrestor wires were retrofitted, as can be seen across the country. But of course they can be lethal too as they are under tension, and there have been incidents of failure or non performance due to poor maintenance of them.

And so, a raised earth median, retained by a continuous concrete barrier, is the safest option of all.

When it comes to lane widths, they have never been reduced. They were always 3.5 metres for motorways and in some newer cases are actually 3.75 metres. There may be an optical illusion there with 3 running lanes and a raised median etc, but in any case, you are mistaken.

And so generally, the newer the motorway section, the safer it is for users.

I think your real question is about aesthetics, but they aren't really relevant against other considerations.

Chris_5339762

The only thing I think they really should have done is kept it wide median up until the M7/8 split. Its wide median up to Portlaoise and I know traffic levels wouldn't need D3 for many, many years, but it still seemed short sighted. Especially when M6 from Rathmorrisey to Galway WAS built as wide median.

Charles Babbage

There has been a reduction in standards, the hard shoulder is narrower, and not only have street lights not been fitted on new sections but they have vandalised the existing street lights. Notably though, despite the reduction in service the increase in tolls proceeded regardless.

dublincc2

https://www.boards.ie/discussion/comment/123657893#Comment_123657893

I am sure you are incorrect re lane widths. The first motorways built in the state were 3.75m and the newer ones were 3.5.

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John_Rambo

When I get outside Dublin into the MidWest and SouthEast I’m genuinely impressed by the road surfaces, especially the motorways. They’re like billiard tables, smooth, well marked, effective rumble strip edging, good drainage and good visibility… and practically empty. Obviously very well engineered. The only added thing I can think of is variable speed limits in bad weather for people with low IQ.

When you drive abroad you really appreciate Irish Motorways.

GPoint

https://www.boards.ie/discussion/comment/123659636#Comment_123659636

Have you driven in France?

Road surface is absolute shite on motorways here except a section of M7 that was re done recently and much shorter patch on the M4 one way (westbound still work in progress)

Even re surfaced M4 is noticeably bumpy.

Agree on the road marks and cat eyes these are very good.

John_Rambo

https://www.boards.ie/discussion/comment/123659727#Comment_123659727

I drive in France every year, and Portugal and Spain. Irish Motorways are far superior. Have to say, I don't agree with you regarding the M7 and the M4. I'm on them a lot and I find them excellent. In good weather I'd say they're suitable for even faster speeds than €120 in some cases.

Irish motorways are generally of higher quality than French ones, they are wider, newer, and better maintained. Surfaces are smooth, markings are bright, signage is consistent, and safety features like rumble strips and smart drainage are standard. Ireland’s network might be smaller, but what exists is built to a very high standard.

In contrast, while France has a far more extensive motorway system, much of it is older, narrower, and worn, especially on tolled routes where you would expect better. Lane widths, road shoulders, and surface consistency can vary wildly. Plus, you are paying through the nose for the privilege.

KrisW1001

The UK standard was 12 feet, or 3.65 m (the US still uses this). 3.75 is the German standard for rural Autobahns, which we adopted for “Rural Motorways”

Even in Germany, most urban stretches and lane-widening projects on existing Autobahns typically use 3.5 m lanes today. Both the UK and German networks were originally envisaged to operate with no speed limits. Of course, “no speed limits” in the mid-1930s meant around 150 km/h, and even in the 1960s, “100 mph” (160 km/h) was still not something the average motorist could dream of. It was still a selling point into the early 1980s if a particular model of an affordable car could break the 100mph barrier. What changed was steering and roadholding. Old cars that had directly-coupled steering need constant adjustment to keep them driving straight; modern cars with power steering will self-centre.

As @Larbre34 says, soft medians are not superior to hard barriers. A soft-median allows a vehicle to leave its own carriageway and suddenly appear as a head-on collision threat on the other. A hard barrier absorbs a lot of the momentum of the car, then throws it back into the same carriageway, where there’s a greater chance that the other drivers can react to it, having already seen it hit the barrier. Sorry to be blunt, but the central median isn’t for the safety of the crashing driver: if you drive onto the median on a motorway, you’re most likely already dead, so the goal is to stop you taking more people with you.

Next, lights: You don’t put streetlights on any rural road (motorway or not) except on the approach to busy exits, or where the road is already in a built-up area. The M7 did not have lights except at its junctions. M50 kept its streetlights when widened. Nothing has changed, this is a non-argument.

Lane width has changed because times move on, and as well as cars needing less of a margin for steering error, we learn more about how the geometry of a road affects safety. Just like hard barriers being safer than soft medians, narrower lanes are shown to be better than wide ones. “Common Sense” doesn’t beat observed data.

It’s now fairly well understood that above 3.5 metres, adding width to a road lane doesn’t make it safer. In fact, there is more evidence that it makes the road more dangerous, as the wider lane gives the driver a distorted sense of how fast they are really travelling.

German Autobahns in rural areas have 3.75 m lanes, but when lanes are added to rural sections now, the new, fastest-traffic, lanes are only built at 3.5 m - even in sections with no speed restriction. France’s entire Autoroute network, commenced in the late 1970s, has 3.5 m lanes. It is one of the safest in Europe. (290 fatalities across the 11,600 km network; versus 800 across Germany’s 16,000 km network in 2022).

Moaning about road tolls can be done on the “Motoring” forum, but tolls are nominally levied for upkeep of existing roads, not building of new ones: I don’t know any case where a road was narrowed after the tolling began. (M50 gained lanes; the original lanes were 3.5 m)

Mrs Dempsey

https://www.boards.ie/discussion/comment/123659132#Comment_123659132

The M7 could do with a 3rd lane between J29 & J30 (N24 - M20) now.

DumbBrunette

https://www.boards.ie/discussion/comment/123661258#Comment_123661258

It appears to have a wide median so could be done relatively easily.

SeanW

https://www.boards.ie/discussion/2058420130/why-was-the-standard-of-motorways-downgraded

I wouldn't call the changes a "downgrade" though IMHO there have been drawbacks.

As other posters have said, the new standard is actually safer because a concrete barrier in the median prevents head-on collisions. And it's cheaper because the land take and structure count is reduced.

The downside is IMHO that if a bridge ever needs to be taken out of service e.g. for maintenance/repair, the entire motorway would have to be closed instead of just one carriageway - some places when that happens and they have two separate carriageways they put a temporary roadway connecting the two and have one lane each way crossing the remaining bridge so the other can be worked on without closing the road in either direction. I also used to like it when the centre foliage was higher, as you could use your high beams at night if traffic was low on your side.

Larbre34

https://www.boards.ie/discussion/comment/123659210#Comment_123659210

Street lights?

Only a tiny percentage of the Motorway network is illuminated. In fact, I can only think of the M50 and M11 section to Bray South and M1 to Lissenhall that are fully lit.

Perhaps some other sections that are near cities are lit too, but apart from junctions, I would estimate that of the 1,000 or so kms of motorway in Ireland, only about 70 kms are lit.

VeryOwl

I wish the signage was properly illuminated on Irish motorways and roads like it is in the UK for example. Why did they stop fitting illumination lamps above signs? You can see some on a few older roads but none of the newer ones.

Sid 1984

Some interchanges leave a lot to be desired & I cannot see how they are in line with EU standards.

Junctions 13 & 14 on the M18 are perfect examples; very short filter lane leading to a hard right angle turn to exit with an equally short joining lane.

L1011

https://www.boards.ie/discussion/comment/123661664#Comment_123661664

Drive on Spanish motorways to see what meets the standard in other EU countries...

KrisW1001

https://www.boards.ie/discussion/comment/123661580#Comment_123661580

Modern signs are highly reflective and can be seen from a distance by the light of headlights alone.

Over-lighting is another one of those things that sounds safe but isn't. In the dark, it's safer if you can see nothing except other cars, the road markings and the signs. Your headlights do that quite well.

If you add additional Illumination, it creates more visual clutter (shadows, half-visible roadside structures) and can affect night vision... this is why driving in twilight is more tiring than driving in darkness.

Charles Babbage

https://www.boards.ie/discussion/comment/123661528#Comment_123661528

The M1 is no longer illuminated to Lissenhall, a busy junction, which illustrates my point about downgrades. You can argue that it is a justified downgrade, that people's eyesight has improved in the last 20 years, but it is a downgrade nonetheless.

John_Rambo

https://www.boards.ie/discussion/comment/123662224#Comment_123662224

They weren’t needed. They were inefficient, expensive, and switching them off has had zero negative impact. Modern motorway signage is vastly improved thanks to high-performance reflective materials that work brilliantly without power hungry lights. Removing outdated infrastructure isn’t a downgrade.

Charles Babbage

https://www.boards.ie/discussion/comment/123662277#Comment_123662277

If street lights are no use then when do they remain on the M50? There was scope to replace them with more efficient LED lights and solar charging to entirely remove any co2 effect, if that was a concern.

John_Rambo

https://www.boards.ie/discussion/comment/123662302#Comment_123662302

Because the M50 is an urban motorway and like all urban motorways in Europe with higher traffic volumes, lower speed limits, and more frequent junctions, it needs lighting.

PixelCrafter

https://www.boards.ie/discussion/comment/123662325#Comment_123662325

I actually thought removing lighting from the N40 in Cork was a hugely retrograde step for that reason. You're going from street lighting into dark road now which is really odd in an urban area. Seemed very much like dogmatic overkill tbh.

MrMusician18

https://www.boards.ie/discussion/comment/123660036#Comment_123660036

You are definitely wrong on the motorway lighting. Junction lighting has been much curtailed in recent years with many light posts made redundant and/or removed.

Larbre34

https://www.boards.ie/discussion/comment/123662224#Comment_123662224

No I wouldn't argue that at all, in fact I daresay general eyesight is worsening with screen exposure.

The M1 should absolutely be lit to Lissenhall, and probably Balbriggan really.