M50 Speed Limit

lad12

Why is the current speed limit on the M50 100kmph? I thought this was to do with work that was being done over the last few years but now this is pretty much complete it is still 100kmph..And yes some parts were 80kmph while it was being widened. Anybody know if it is likely to be increased to the motorway speed limit of 120kmph? The south part of the M50 is still 120kmph. I have read its due to 3 lanes yet the very end of the m50 that joins the M11 is 3 lanes and it is 120kmph. Its a bit of joke considering some of the national roads around Galway/Mayo are 100kmph yet they can barley fit two lanes on them.

unkel

lad12 wrote: »

Anybody know if it is likely to be increased to the motorway speed limit of 120kmph?

Nope it will stay at 100km/h.

lad12

Do you know what the reason is for this?

maglite

Urban Motorway speed limit apparently.

pippip

It's 100kph because to fit all the lanes they have been made narrower than Motorway standard. They class it as an urban motorway, although I've never found the official classification of this.

Sids Not

I've driven through it plenty of times at 120...even with garda cars around...no-one sticks to 100

lad12

Oh ok so its to do with lane? I wonder was this in their original plans or a calculation error :-)

lad12

Sids Not wrote: »

I've driven through it plenty of times at 120...even with garda cars around...no-one sticks to 100

Yes I have done this but I thought these 100kmph signs were still up from the development days especially when 1 end of the road is 120kmph.

Plus ya never know you might get some garda who will do you for this.

Guy:Incognito

lad12 wrote: »

Oh ok so its to do with lane? I wonder was this in their original plans or a calculation error :-)

The original plans only had 2 lanes in each direction as it was until the upgrades. It now has 4.

the_syco

There's a "100" sign every couple of meters in case you forget

lad12

Yeah true..I just watched that traffic blues program from RTE..They pulled a guy with a lorry because of debris coming off the truck..One of the cops says.."Loose material coming off the back of truck and cars going along the motorway at 120KMPH" :-)

Sids Not

[QUOTE=lad12;73227293
Plus ya never know you might get some garda who will do you for this.[/QUOTE]

Doubt it...you're probably really only doing 115...which would be around their "flexible rates".....:D...i.e 10%+2 kph....unless you actually overtake them at that speed....

Dartz

It might have something to do with the camera vans and speed traps all along it.

Reloc8

Sids Not wrote: »

Doubt it...you're probably really only doing 115...which would be around their "flexible rates".....:D...i.e 10%+2 kph....unless you actually overtake them at that speed....

?

That would be 104 (the 'flexible' rate).

I see plenty of people being done for speeding at 55 in a 50, 65 in a 60, 105 in a 100.

godtabh

Reloc8 wrote: »

?

That would be 104 (the 'flexible' rate).

I see plenty of people being done for speeding at 55 in a 50, 65 in a 60, 105 in a 100.

its actually 112 (100*10% +2 = 112)

The road widths are narrower and hence the smaller speeds but as per usual no one give a crap

Cookie_Monster

lad12 wrote: »

Why is the current speed limit on the M50 100kmph?.

Lazy planning and design.

Limerick Rebel

There are speed camera reference lines on the motorway in a couple of areas. I presume there is a fixed speed cameras at these points. There is one very noticable one near the M1 interchange where I believe the speed limits drops down to 80km/hr. Has anybody ever received penalty points for being over the speed limit at this point?

Cookie_Monster

Limerick Rebel wrote: »

There are speed camera reference lines on the motorway in a couple of areas. I presume there is a fixed speed cameras at these points. There is one very noticable one near the M1 interchange where I believe the speed limits drops down to 80km/hr. Has anybody ever received penalty points for being over the speed limit at this point?

nope, no cameras in place as yet

Gary ITR

Isn't that whole 10% + 2kph a myth?

Sids Not

Onkle wrote: »

Isn't that whole 10% + 2kph a myth?

KWYM......;);)

godtabh

Cookie_Monster wrote: »

Lazy planning and design.

in what way?

in terms of planning the got the economic forecasts wrong but the engineering side of things were correct based on information supplied.

Cookie_Monster

godtabh wrote: »

in what way?

it's not capable of safely allowing 120kph so not designed properly as a motorway. Not wide enough so lanes have to be narrower, poor sightlines in places along the southern parts mean it's only 100.

Lemming

pippip wrote: »

It's 100kph because to fit all the lanes they have been made narrower than Motorway standard. They class it as an urban motorway, although I've never found the official classification of this.

I think some of Dublin's road dis-management folks should take a drive on the m60 as it runs south around Manchester. Narrow lanes anyone? of course. Lower speed limit? Pfffft. Of course not; just stick up warnings of lane narrowing for 'n' distance.

This whole "urban motorway" thing smells of "cute h000r LOOOIKE BAI!!" syndrome.

godtabh

Cookie_Monster wrote: »

it's not capable of safely allowing 120kph so not designed properly as a motorway. Not wide enough so lanes have to be narrower, poor sightlines in places along the southern parts mean it's only 100.

accept its not a motorway and whats the problem? Speed limits go up and down regularly during road upgrade works. The road is safe for 100kph. sounds like good design to me.

If the speed limit was 120kph and designed for 100kph there would be a definite gripe then.

The M50 of old and M50 of now are two totally different road networks

privateBeavis

Civil engineer friend told me at the time they were still working on it, it was going to be staying at 100kph because of the curvature of some of the bends being two tight to allow 120kph!!

Cookie_Monster

godtabh wrote: »

accept its not a motorway and whats the problem?

well then designate it as not a motorway and allow non motorway traffic to use it... problem solved

lad12

Exaclty It can hardly be called a motor way with the 100kmph speed limit..And this whole lane size is a bit of a joke..As I said earlier there are roads around Galway and Mayo that can barley take 1 car and they have a speed limit of 100kmph. When you compare the M50 to these its a bit of a joke. There is a question in the driver theroy test that asks what is the speed limit on a motorway and I would answer 120kmph but this obviously isnt the answer any more. The correct answer should be..well..we will make it up as we go along.

Marcusm

Onkle wrote: »

Isn't that whole 10% + 2kph a myth?

Maybe it's being assumed here as it's regularly referenced by senior police officers in the UK. THe logic goes along the lines that govt standards mandate the speedometer can be inaccurate by up to 10% either way and not fail build standards. I suspect concern about the ability to enforce the law when the govt has assisted in the driver being unaware of his actual speed led to the relaxation. However, in the event that someone is caught driving in excess of the speed limit + 10% + 2mph they are assessed for fines and points from the actual speed limit and not the soft boundary. No idea whether a similar rule if in application in Ireland. Probably could find out under FoI unless Garda Siochana is exempt.

Joe 90

Marcusm wrote: »

Maybe it's being assumed here as it's regularly referenced by senior police officers in the UK. THe logic goes along the lines that govt standards mandate the speedometer can be inaccurate by up to 10% either way and not fail build standards. I suspect concern about the ability to enforce the law when the govt has assisted in the driver being unaware of his actual speed led to the relaxation. However, in the event that someone is caught driving in excess of the speed limit + 10% + 2mph they are assessed for fines and points from the actual speed limit and not the soft boundary. No idea whether a similar rule if in application in Ireland. Probably could find out under FoI unless Garda Siochana is exempt.

I think that you'll find that the speedo may over read by up to 10% but cannot under read. At least, that used to be the law.

That being the law, speedos are or were, generally deliberately calibrated to over read so that the owner would have an optimistic view of the performance of his car. Similarly, mileage/trip recorders were also calibrated to over read to give an optimistic version of the cars economy and to shorten the real service interval.

I would expect the same degree of honesty to apply to the MPG displays on modern cars.

Marcusm

I don't know anything about the technicalities of the speedo and maybe what I quoted is an urban legend as I cannot find an official quote for it. However, although only of interest rather than application in Ireland, set out below is an extract from the Assoc of Chief Police Officers in UK relating to prosecutions for speeding. (JUly 2000)

The Guidance

ACPO's guidance has been formulated having taken account of the need for proportionality (especially with the introduction of Human Rights legislation) and the need for targeting in order to maximise the potential of scarce police resources and make a substantial contribution to the multi-agency road death and injury reduction effort.

Driving at any speed over the limit is an offence. The differing speed limits are generally related, and proportionate, to the risks to all road users using that road. Where police officers consider that an offence has been committed i.e. that a motorist has driven at any speed over the relevant speed limit, they should consider whether it is appropriate to take enforcement action against the offender.

The Police Service now uses technology that enables it to prove that an offence has been committed as soon as a driver exceeds the relevant speed limit by a very small margin. Motorists will therefore be at risk of prosecution immediately they exceed any legal speed limit.

The guidance to police officers is that it is anticipated that, other than in the most exceptional circumstances, the issue of fixed penalty notices and summonses is likely to be the minimum appropriate enforcement action as soon as the following speeds have been reached:
LimitFixed PenaltySummons
20 mph25 mph35 mph
30 mph35 mph50 mph
40 mph 46 mph66 mph
50 mph57 mph76 mph
60 mph68 mph86 mph
70 mph79 mph96 mph


Fixed penalty of
1. £60 (pending)
2. Licence endorsed with 3 penalty points


Summons: Magisterial discretion (level 2) maximum of:
1. £1000 fine
2. Licence endorsed - range of penalty points available
3. Disqualification
4. Compulsory re-testing
This guidance does not and cannot replace the police officer's discretion and they may decide to issue a summons or a fixed penalty notice in respect of offences committed at speeds lower than those set out in the table. Moreover, in particular circumstances, driving at speeds lower than the legal limit may result in prosecution for other offences, for example dangerous driving or driving without due care and attention when the speed is inappropriate and inherently unsafe.

ted1

It's an urban motorway and as such has a greater number of entries and exits over a short distance which is the reason for the lower limit. The entry exits result in a much higher number of lane changes than a interconnector motorway would have.

slimjimmc

lad12 wrote: »

Exaclty It can hardly be called a motor way with the 100kmph speed limit..And this whole lane size is a bit of a joke..As I said earlier there are roads around Galway and Mayo that can barley take 1 car and they have a speed limit of 100kmph. When you compare the M50 to these its a bit of a joke. There is a question in the driver theroy test that asks what is the speed limit on a motorway and I would answer 120kmph but this obviously isnt the answer any more. The correct answer should be..well..we will make it up as we go along.

Why not? A motorway is not defined by a speed limit, it's defined by it's design and rules. A motorway is restricted to certain vehicles, has only merging junctions, no T-junctions, entrances to fields or houses , and has different rules regarding stopping and the hard shoulder.

The 120km/h is the maximum speed limit which can be assigned to a motorway and in general that is what is usually applied, but that doesn't mean a motorways must only be 120km/h, a lower limit can be used when and where the authorities deem it appropriate.

So the correct answer would be, 120km/h is the highest speed limit which is generally applied to motorways but lower limits can be in force instead.

Tails142

To put this into perspective...

The M50 from the M1 junction in the north, to the Sandyford junction in the south is just over 30 kilometres.

Travelling 30 kilometers at a speed of 120km/hr takes 15 mins.

Travelling 30 kilometers at a speed of 100km/hr takes 18 mins.

I imagine that the majority of people do not travel the full 100km/hr zone of the M50 so if you only do part of it, the delay caused is even less than 3 minutes.

If you only travel a few junctions the delay is probably less than 60 seconds. Which you may easily gain/lose at the next set of traffic lights you come to once you leave the M50.

Coupled with the fact that due to high traffic volumes, traffic would rarely travel at 120 km/hr in any case the delay is made even more trivial.

Case closed

munchkin_utd

also, traffic dynamics has a part to play.

By reducing the limit on a very busy stretch of road you get less domino effect traffic jams.

They start by people slaming on the brakes, which causes other drivers to brake in a cascade till everyone is stopped. The higher the limit the more braking there is and more chance of a jam being caused.

There was a nice illustration of this on telly a while back.
They got a number of people to drive in a circle a couple of 100m in diameter.
They first drove at a brisk but not fast pace and they carried on for ages with no probs.
When they drove at a higher speed, it was harder to maintain the distances so the people ended up braking far more and came to a standstill very quickly.

Iwannahurl

I was going to mention congestion, but you beat me to it.

I guess that in this area, given the traffic volumes, a lower speed limit helps to reduce the likelihood of congestion.

Either that or a speed limit of 120 is safer/more manageable in an area with higher traffic volumes, especially given the number of on-off ramps as someone pointed out earlier.

jmayo

lad12 wrote: »

Why is the current speed limit on the M50 100kmph? I thought this was to do with work that was being done over the last few years but now this is pretty much complete it is still 100kmph..And yes some parts were 80kmph while it was being widened. Anybody know if it is likely to be increased to the motorway speed limit of 120kmph? The south part of the M50 is still 120kmph. I have read its due to 3 lanes yet the very end of the m50 that joins the M11 is 3 lanes and it is 120kmph. Its a bit of joke considering some of the national roads around Galway/Mayo are 100kmph yet they can barley fit two lanes on them.

That would be my thinking as well.
Except I would say how come some one track roads with grass growing up the middle and hedges growing out into the road has speed limit of 80 kph whereas a four lane road with all traffic going the one way and claar views ahead has speed limit of 100kph.

Only in Ireland. :rolleyes:

Sids Not wrote: »

I've driven through it plenty of times at 120...even with garda cars around...no-one sticks to 100

Beware I have seen them pull people over.

godtabh wrote: »

...
The road widths are narrower and hence the smaller speeds but as per usual no one give a crap

See above please.

godtabh wrote: »

accept its not a motorway and whats the problem? Speed limits go up and down regularly during road upgrade works. The road is safe for 100kph. sounds like good design to me.

If the speed limit was 120kph and designed for 100kph there would be a definite gripe then.

The M50 of old and M50 of now are two totally different road networks

Yeah the old two lane road had speed limit of 70mph and then when they upgraded it by adding lanes, more proper filter lanes, better off ramps, they dropped the speed limit. :rolleyes:

ted1 wrote: »

It's an urban motorway and as such has a greater number of entries and exits over a short distance which is the reason for the lower limit. The entry exits result in a much higher number of lane changes than a interconnector motorway would have.

Ehhh the old road had the same number of junctions I believe and even at one point ended in a dead end or roundabout and yet had a higher speed limit.
So next excuse please.

IMHO the M50 should have a variable speed limit as is case with some other countries.
That way the speed limit could be displayed and dropped according to traffic volumes/weather.
Of course this is Ireland where our planners could not dream up such a solution and our drivers couldn't work out such a complicated system. :rolleyes:

pippip

On the topic of junctions. Yes there is the same amount but they used to be normal slip roads and now they are auxiliary lanes (designed for volume) which have drivers coming off and on the motorway.

That means the same lane is being used for drivers getting up to and decreasing down from the speed limit, which the lower the limit the safer.

Our man in Havana

Marcusm wrote: »

Maybe it's being assumed here as it's regularly referenced by senior police officers in the UK. THe logic goes along the lines that govt standards mandate the speedometer can be inaccurate by up to 10% either way and not fail build standards. I suspect concern about the ability to enforce the law when the govt has assisted in the driver being unaware of his actual speed led to the relaxation. However, in the event that someone is caught driving in excess of the speed limit + 10% + 2mph they are assessed for fines and points from the actual speed limit and not the soft boundary. No idea whether a similar rule if in application in Ireland. Probably could find out under FoI unless Garda Siochana is exempt.

That info would be withheld under FOI, as it would assist offenders break the law.

jmayo

pippip wrote: »

On the topic of junctions. Yes there is the same amount but they used to be normal slip roads and now they are auxiliary lanes (designed for volume) which have drivers coming off and on the motorway.

That means the same lane is being used for drivers getting up to and decreasing down from the speed limit, which the lower the limit the safer.

Eh but before the slip lanes were probably shorter and becasue of design and traffic lighted roundabouts (e.g Naas road exit + redcow roundabout) traffic was backing and slowing on motorway and probably caused even greater cause for concern.

seamus

In my experience, it's much safer to do 120kph/70mph on the M50 now than it was previously. More lanes, longer slip roads, better median.

pippip

jmayo wrote: »

Eh but before the slip lanes were probably shorter and becasue of design and traffic lighted roundabouts (e.g Naas road exit + redcow roundabout) traffic was backing and slowing on motorway and probably caused even greater cause for concern.

Yes in the past they backed up so the new design was based on handling volume. The new design of auxiliary lanes is not designed on achieving speed.

The old slips had single merging (one line of traffic entering another with acceleration). the auxiliary lanes have two way traffic merging (both into each other with both acceleration and deceleration).