New Motorways - design flaw in heavy rain?

Matt406

Does anyone else agree that the new motorways in this country retain a lot of water on their surface during heavy rain? Maybe it’s just me but I think that when there is any substantial amount of rain a layer of water just sits on the motorways! I don’t notice the same thing on the few older motorways that we have – i.e. this morning I drove from Kilkenny to Dublin. The M9 had a layer of water sitting on it up until the Kilcullen exit where you are on the older section of motorway. There was still water on this older section but no where near as much! Is this my imagination or does anyone else agree? If so this surely should not be the case – have these motorway been designed incorrectly?

keithclancy

Matt406 wrote: »

Does anyone else agree that the new motorways in this country retain a lot of water on their surface during heavy rain? Maybe it’s just me but I think that when there is any substantial amount of rain a layer of water just sits on the motorways! I don’t notice the same thing on the few older motorways that we have – i.e. this morning I drove from Kilkenny to Dublin. The M9 had a layer of water sitting on it up until the Kilcullen exit where you are on the older section of motorway. There was still water on this older section but no where near as much! Is this my imagination or does anyone else agree? If so this surely should not be the case – have these motorway been designed incorrectly?

Not just Ireland, Germany and Belgium have motorways where this happens too.

Its all down to the maintenance at the side of the road, making sure the drainage is clear.

smash

All the way down the M7 there's signs "Road liable to flooding"

Berty

Roads, having worked on them before, are built to EU standards with an incline built into them to handle a certain amount of water.

Not a months rain in 24 hours of course so the motorways will have standing water. No escaping it really.

The roads have an incline so the water will run off to the side, also the centre median barrier have bore holes in them to allow heavy water(and small animals sometimes) to move through the holes rather than building up along the barrier.

smash wrote: »

All the way down the M7 there's signs "Road liable to flooding"

Does that include the N7 though because that is a fairly old national route that nearly always floods by Citywest?

senordingdong

Is it the same uniform EU standard for all countries? Seems unusual when some would clearly get more rain than others.

The matter that I would take issue with is not how much water can run off the motorway, but where does it go afte that?
In most cases I find there is no where for the water to go once it has flown off the road and eventually just builds up.

Should there not be something more in terms of drainage at the edgse of the road?

bazz26

The best drainage systems in the world would struggle with the rain we have had in the last 24 hours.

mickdw

senordingdong wrote: »

Is it the same uniform EU standard for all countries? Seems unusual when some would clearly get more rain than others.

The matter that I would take issue with is not how much water can run off the motorway, but where does it go afte that?
In most cases I find there is no where for the water to go once it has flown off the road and eventually just builds up.

Should there not be something more in terms of drainage at the edgse of the road?

There are drainage systems at the roadside. Also there is a certain permeability to the road surface. I feel that older surfaces tend to drain through better.

pippip

mickdw wrote: »

There are drainage systems at the roadside. Also there is a certain permeability to the road surface. I feel that older surfaces tend to drain through better.

True but at the cost of road noise

Farmer Pudsey

Beer Baron wrote: »

Not a months rain in 24 hours of course so the motorways will have standing water. No escaping it really.
QUOTE]

We got the amount of rain that we normally get in the whole of june in the last 36 hoursnot a normal months rain we often get 8-10" (200-250mm) in a month in winter. It is quite common to get 2"(50mm) of rain in Ireland in that time frame it usually happen at least once every year and maybe 3-4 times. Getting around an inch (20-30mm) is very very common

It amazes me the inability of engineers to allow for that. Every winter it happens and we get the excuse that it is one off or global warming it has been happening since I was knee high.

We then get the excuse European standards every country should use the European standards as a minimum and adapt them for there own situtation. In Ireland we average around 40" (1000mm) of rain in any year however it varies from as much as 80" (2000mm) in the south west to around 28" (700mm) in places in the east so in doing any engineering job it sould be taken into account.

It would be like putting a dirt track between two new small town centres and saying it was european standards you have to take local conditions imto account.

senordingdong

mickdw wrote: »

There are drainage systems at the roadside. Also there is a certain permeability to the road surface. I feel that older surfaces tend to drain through better.

But are they adequate?
What might seems adequate for Spain or Italy may not be adequate for UK or Ireland.

furtzy

Seems to depend on the surface type. The M2 was built in 2 sections. The first section Dublin to Ashbourne has a surface water problem but the last section north of Ashbourne is fine as it has a different surface finish.

senordingdong

Isn't the Dublin - Ashbourne part just a matter of the hills that the road traverses?
I mean that dip at Kilshane Cross is HUGE! So even if the drainage is built to standard, they can't ignore gravity.

And an utter nightmare when the road freezes.

furtzy

Theres a distinct surface change after the Ashbourne South exit. All surface spray stops instantly. You'll even notice less tyre noise as well

Organic Cavity

Didn't they make a new type tarmac so there was less surface water?

conzy

I actually find the newer stretches of the M9 more liable to retaining surface water. As soon as you get to the older rougher tarmac of the M7 there seems to be less surface water, the car definitely feels more planted anyway.

urajoke

Organic Cavity wrote: »

Didn't they make a new type tarmac so there was less surface water?

=

GavMan

It's not just rain like we've had the last 2 days. Even a standard amount of rain we'd see in winter leave a lot of standing water

Matt406

conzymaher wrote: »

I actually find the newer stretches of the M9 more liable to retaining surface water. As soon as you get to the older rougher tarmac of the M7 there seems to be less surface water, the car definitely feels more planted anyway.

I agree 100% conzymaher. That was my experience this morning!

Paddy@CIRL

Actually, for anyone who regularly travels the M9, have you noticed that the driving lane seems to hold a lot more water than the overtaking lane?

Boscoirl

the stretch of the M7 just before the first exit for Nenagh when coming from Limerick is lethal, it is a bit downhill, so that will affect it, but you have very little say where your car is going sometimes, not just in extremely heavy showers.

Cuddlesworth

Paddy@CIRL wrote: »

Actually, for anyone who regularly travels the M9, have you noticed that the driving lane seems to hold a lot more water than the overtaking lane?

You need somebody to drive in the lane to displace water.

the culture of deference

The N4 lucan inbound (from under the woodies/foxhunter exit up to liffey valley) is awful with the run off coming down the hill.

People are still driving up each others arses at 80 + kmh.
Its Crazy. Whats wrong with people.