Noisy surfaces

niloc1951

Just back after seven weeks driving on continental roads, apart from other differences the thing which I noticed most as I headed home from Rosslare was the much louder road noise our surfaces create compared to what I had become accustomed to.

What's so different about our surfaces and surely such a characteristic increases vehicle wear and tear and driver fatigue.

And BTW I know some sections of our new MW's have low noise surfaces.

iMe

The difference in noise levels is due to the use of different types of surface courses used. Road noise is created by little pockets of air being compressed between the tyre and road, hence different types of surface textures create different levels of road noise. A surface texture that allows some movement of air and means that the air isn't compressed as much, will be quieter. So in general a porous asphalt will be quietest, hot rolled asphalt the loudest and stone mastic asphalt or thin asphalt surfaces somewhere in between.

In Ireland hot rolled asphalt would be the predominately used surface course, hence why you noticed the more road noise here than you did on continental roads where it would be mostly stone mastic asphalts or similar materials used. Hot rolled asphalt would be used very seldom on the continent. A lot of the motorways in Ireland now have stone mastic asphalt, thin surface courses, or in a few small sections porous asphalt, hence the lower noise on these sections.

In terms of vehicle wear and tear I would imagine that there would be little or no difference between the different types of surfaces.

niloc1951

iMe wrote: »

The difference in noise levels is due to the use of different types of surface courses used. Road noise is created by little pockets of air being compressed between the tyre and road, hence different types of surface textures create different levels of road noise. A surface texture that allows some movement of air and means that the air isn't compressed as much, will be quieter. So in general a porous asphalt will be quietest, hot rolled asphalt the loudest and stone mastic asphalt or thin asphalt surfaces somewhere in between.

In Ireland hot rolled asphalt would be the predominately used surface course, hence why you noticed the more road noise here than you did on continental roads where it would be mostly stone mastic asphalts or similar materials used. Hot rolled asphalt would be used very seldom on the continent. A lot of the motorways in Ireland now have stone mastic asphalt, thin surface courses, or in a few small sections porous asphalt, hence the lower noise on these sections.

In terms of vehicle wear and tear I would imagine that there would be little or no difference between the different types of surfaces.

"A surface texture that allows some movement of air and means that the air isn't compressed as much, will be quieter. So in general a porous asphalt will be quietest, hot rolled asphalt the loudest and stone mastic asphalt or thin asphalt surfaces somewhere in between."

Considering this country experiences such a high annual rainfall it seems difficult to understand why a porous asphalt isn't commonly uses for wet weather safety reasons, apart altogether from the environmental road noise reasons in relation to both adjacent residential properties and in vehicle

I notice there is no reference to the effects of the extra noise in relation to driver fatigue.

iMe

Porous asphalt is good at reducing noise and spray in wet conditions but there are also many other factors that have to be considered in selecting the type of surface course apart from just these. Porous asphalt has several disadvantages too, in particular it has a significantly shorter lifespan.

I should also add that the other types of surfaces do have a texture to allow for the drainage of water along with having adequate crossfall/camber (there are standards in place for these) to ensure wet weather safety. (Also, as a side note, having enough tyre thread depth is really important in this too)

It much more a case of selecting the best solution for the individual situation rather than always using one particular type.

There's several factors involved in driver fatigue, but from the information I've seen the role of road noise (if any) is fairly minor compared to the other ones, e.g. lack of sleep or poor sleep, internal body clock,time-on-task, monotonous tasks, individual characteristics including medical conditions.

Alun

They were mad on using that stuff in the Netherlands years ago too, but like you said, it's lifespan was shorter, esp. when heavy trucks used it, plus despite it resulting in shorter stopping distances in the wet, stopping distances in the dry were actually worse than normal asphalt.

niloc1951

iMe wrote: »

Porous asphalt is good at reducing noise and spray in wet conditions but there are also many other factors that have to be considered in selecting the type of surface course apart from just these. Porous asphalt has several disadvantages too, in particular it has a significantly shorter lifespan.

I should also add that the other types of surfaces do have a texture to allow for the drainage of water along with having adequate crossfall/camber (there are standards in place for these) to ensure wet weather safety. (Also, as a side note, having enough tyre thread depth is really important in this too)

It much more a case of selecting the best solution for the individual situation rather than always using one particular type.

There's several factors involved in driver fatigue, but from the information I've seen the role of road noise (if any) is fairly minor compared to the other ones, e.g. lack of sleep or poor sleep, internal body clock,time-on-task, monotonous tasks, individual characteristics including medical conditions.

Porous asphalt has several disadvantages too, in particular it has a significantly shorter lifespan

So, why it's use so widespread in Europe where traffic and particularly HGV traffic is soooo much heavier than here, surely Value For Money is important over there too.

L1011

niloc1951 wrote: »

Porous asphalt has several disadvantages too, in particular it has a significantly shorter lifespan

So, why it's use so widespread in Europe where traffic and particularly HGV traffic is soooo much heavier than here, surely Value For Money is important over there too.

Its no longer in widespread use there. When it wears out it is generally replaced with a non-porous surface.

niloc1951

MYOB wrote: »

Its no longer in widespread use there. When it wears out it is generally replaced with a non-porous surface.

So what's the reason their roads currently create so much less road noise and vibrations that ours, as a rule.

L1011

niloc1951 wrote: »

So what's the reason their roads currently create so much less road noise and vibrations that ours, as a rule.

They don't, as a rule. Have you ever tried driving in Belgium?

niloc1951

MYOB wrote: »

They don't, as a rule. Have you ever tried driving in Belgium?

Yes they do, FYI my comment is based on seven weeks recently spent driving in Europe, plus all the rest.

And Yes I have driven in Belgium, they have their own political and administrative problems and their lack road maintenance programs has resulted in their deterioration to conditions as bad as our were at one time. Someone once commented in jest that perhaps they had not gotten around to repairing the WWII damage.

L1011

niloc1951 wrote: »

Yes they do, FYI my comment is based on seven weeks recently spent driving in Europe, plus all the rest.

And Yes I have driven in Belgium, they have their own political and administrative problems and their lack road maintenance programs has resulted in their deterioration to conditions as bad as our were at one time. Someone once commented in jest that perhaps they had not gotten around to repairing the WWII damage.

When those surfaces are life-expired they are highly unlikely to be replaced with porous surfaces.

You seem to be seriously over-exaggerating the proportion of roads laid with it on the continent, at that.

niloc1951

MYOB wrote: »

When those surfaces are life-expired they are highly unlikely to be replaced with porous surfaces.

You seem to be seriously over-exaggerating the proportion of roads laid with it on the continent, at that.

Byeeeeeee

Solair

The other issue is that Irish road surfaces are almost always slightly wet. It's very rare that they're ever fully dried out as rain fall is so frequent.

Could it simply be that you are hearing the tyres interacting with damp tarmac vs bone dry tarmac in France?

We tend to have very rose-tinted views of Irish weather. It is incredibly damp here, even compared to most of England.

fryup

iMe wrote: »

In Ireland hot rolled asphalt would be the predominately used surface course, hence why you noticed the more road noise here than you did on continental roads where it would be mostly stone mastic asphalts or similar materials used. Hot rolled asphalt would be used very seldom on the continent. A lot of the motorways in Ireland now have stone mastic asphalt, thin surface courses, or in a few small sections porous asphalt, hence the lower noise on these sections.

.

is hot rolled asphalt the bumpy sharp gravel material?? used on secondary roads?

L1011

fryup wrote: »

is hot rolled asphalt the bumpy sharp gravel material?? used on secondary roads?

Possibly. Depends how bumpy and how secondary you mean.

HRA has gravel in it, but its not particularly sharp or bumpy by any means.

I'm not sure what's used on minor roads here really has a name, its effectively a bitumen layer covered with gravel and is very sharp and bumpy/

Private Joker

fryup wrote: »

is hot rolled asphalt the bumpy sharp gravel material?? used on secondary roads?

Thats surface dressing.

The sma wearing courses are 3 decibels quieter than the hra. The NRA and councils are moving towards the sma wearing courses, they are cheaper to lay and they give a degree of structural strength. The downside is its drainage characteristics and can cause aquaplaning in wet weather and can cause problems at low temperatures with black ice.

Road-Hog

Private Joker wrote: »

Thats surface dressing.

The sma wearing courses are 3 decibels quieter than the hra. The NRA and councils are moving towards the sma wearing courses, they are cheaper to lay and they give a degree of structural strength. The downside is its drainage characteristics and can cause aquaplaning in wet weather and can cause problems at low temperatures with black ice.

I don't want to sound pedantic but SMA (sand mastic asphalt I think it stands for) is no longer used, I think what you are referring to is 'Thin Surface Wearing Course'.......i.e the top 35 to 40mm. Its an all in one operation to lay as in the paving machine lays in one go, no coming back later to roll in chips as with HRA

highwaymaniac

Road-Hog wrote: »

I don't want to sound pedantic but SMA (sand mastic asphalt I think it stands for) is no longer used, I think what you are referring to is 'Thin Surface Wearing Course'.......i.e the top 35 to 40mm. Its an all in one operation to lay as in the paving machine lays in one go, no coming back later to roll in chips as with HRA

Whilst we are being pedantic, SMA stands for Stone Mastic Asphalt and is still in widespread use - all over cork city for example. Thin Surface Wearing Course is now termed Thin Surface Course System and a polymer modified SMA to Cl. 942 of the NRA spec. for roadworks would fall under this heading.

Solair

Shouldn't the NRA and Department of Transport just have a standard that is required for road surfaces?

It seems a bit daft that we've umpteen different types of surface in use, some systems being completely obsolete.

Some of the pot-hole filling systems in use are also laughable. I've seen Cork County Council filling potholes on one of the most heavily used parts of the Rochestown road by just pouring chipping + tar into the holes. Within a week or so, they just fall out again. The holes are so big that they're nearly risky to drive over at anything more than about 15km/h at times!

I can't understand why this kind of thing goes on. Surely it would be more cost effective to do a proper patch rather than doing these pot-hole fills over and over and doing more damage to the road surface in the long term.