Should Melbourne Grove be 20mph?

[James Barber]

Genuine question I'd welcome feedback on.

Melbourne Grove between Lordship Lane and East Dulwich Grove is in two political wards. Village ward to the west and East Dulwich ward to the east.

It has speed cushions already in place and is entirely residential.

Northbound average speed 18.2mph but 85th percentil 22.4mph. That means 15% travel faster than 22.4mph.

Southbound average speed 17.9mph but 85th percentil 21.7mph. That means 15% travel faster than 21.7mph.

So 3 vehicles in every 20 driving at excessive speeds.

Do you think we sohuld make this 20mph?

[LalKJ]

Yes, James I really do think MG should be a 20 mph zone. In fact I emailed you about 6 months ago to discuss the same. I should declare that I am a MG resident, but the speeds that some people race down the road is scary. The speed cushions are totally ineffective and any car larger than a small hatchback can merely straddle the hump with no change to speed. We have a major problem down the road with vans and lorrys which seem to be the worst offenders. People use it as a short cut around Lordship Lane, and seem to just gun it down as fast as possible. Anything that can be down to reduce speeds down Melbourne Grove would be much appreciate by me, and I am sure all MG residents.

[Loz]

James Barber Wrote:

-------------------------------------------------------

> Genuine question I'd welcome feedback on. Melbourne Grove between Lordship Lane and East

> Dulwich Grove is in two political wards. Village ward to the west and East Dulwich ward to the

> east.

>

> It has speed cushions already in place and is entirely residential.

>

> Northbound average speed 18.2mph but 85th percentil 22.4mph. That means 15% travel faster than 22.4mph.

> Southbound average speed 17.9mph but 85th percentil 21.7mph. That means 15% travel faster than 21.7mph.

> So 3 vehicles in every 20 driving at excessive speeds.

Since when has 'excessive' meant 'within the speed limit'?

[MarkE]

It depends upon where those measurements are taken.

I walk the stretch of Melbourne Grove between Chesterfield Grove and East Dulwich Grove both ways each day and very rarely see cars exceeding ~10-15mph, largely due to the volume of cars parked on both sides of the street.

I'd agree that driving in excess of 20mph on that particular stretch would be quite dangerous, but fail to believe that many drivers would get up to that speed anyway.

[Penguin68]

Creating 'piecemeal' 20mph zones is (broadly) unhelpful. There is an argument for properly planned and consulted broad zones - so the drivers in them can be (reasonably) sure of the relevant limits - and these should be properly marked-up with regular speed limit reminders (I have posted elsewhere on the 'Rapel' system used in e.g. France to remind people of the limits). I think (and I live in it) that Underhill is all 20mph - but it is not always clear - and I am regularly hooted at, when going at or just below 20, by drivers who either don't know, or don't care, and wish me either to speed up or to let them over-take.

In many places weight of traffic and of parking mean that 20mph or less is often the only safe speed to go at (sometimes the only possible speed to go at) outwith any formally set limits.

I would be happy for the whole of Dulwich and ED south of Goose Green and bounded by the S Circular to be 20mph as a broad zone, properly marked-up, but odd roads and half roads make no sense and will simply confuse.

I suspect, based on other posts, that Mr Barber is mixing it with fellow councillors in another ward and is using this 'genuine question' as a political stalking horse. His right, of course, as party political politician, ours, not to play the games with him.

[giggirl]

I used to live in Melbourne Grove and it's always been a rat run with drivers putting their foot down. So yes, speed limits please.

[ianr]

Loz Wrote:

> James Barber Wrote:

>> Northbound average speed 18.2mph but 85th percentil 22.4mph. That means 15% travel faster than 22.4mph.

>> Southbound average speed 17.9mph but 85th percentil 21.7mph. That means 15% travel faster than 21.7mph.

>> So 3 vehicles in every 20 driving at excessive speeds.

>

> Since when has 'excessive' meant 'within the speed limit'?

Since when has "excessive" meant "at or above the 85th percentile"?

[d.b]

Agree the numerical reasoning is poor... to define excessive at 85%, then say 3 in 20 are excessive is meaningless. 3 in 20 are "excessive" anywhere and everywhere by that definition.

Pedantry aside, I don't think 22.4mph at the 85th percentile seems very high, actually. That's in keeping with what I see walking down melbourne grove as I do every day, twice a day.

LalKJ, I don't recognize the "major problem", I almost never see lorries, and I don't see traffic "gun down it as fast as possible" either.

Having occasionally driven a hirecar around the area it is not a road to drive fast down, the parked cars and speedbumps do a decent job at slowing you down already. I think a 20mph zone is entirely unnecessary.

[Cora]

Yes it should....cars often race down there when we're trying to cross with kids...

[Loz]

If cars are (allegedly) travelling that fast, Cora, how would changing the speed limit help?

[El Pibe]

I'm amazed anyone can manage more than about 9 ft along MG without having to pull in to let someone past, leave alone achieve excessive speeds.

I tend to think of residential streets with humps as defacto 20mph zones so I don't suppose formalising it hurts.

Of course if someone is pelting it down that road they're probably unlikely to be swayed by some signs. Maybe one of those popular speed camera things? I know people love them!!

[StraferJack]

"If cars are (allegedly) travelling that fast, Cora, how would changing the speed limit help?"

I'm guessing that of the "speeders", a large number are % offenders - ie they like to travel just above the limit - "that's not really speeding"

So the speed of any such impact would be above a new limit but still significantly reduced

[Cora]

Yes always a problem that those speeding obviously don't care about the limit and unlikely to get caught especially on such a short stretch but I think it is more a symbolic limit?

[melbourne groover]

I would like to see a 20 mph limit. I have seen a load of near misses and do a double take at some of the speeds and stops. Not sure if the lower limit would fix this but perhaps worth a try? Would tie in with Chesterfield etc also.

[richard tudor]

Penguin68 Wrote:

-------------------------------------------------------

> Creating 'piecemeal' 20mph zones is (broadly)

> unhelpful. There is an argument for properly

> planned and consulted broad zones - so the drivers

> in them can be (reasonably) sure of the relevant

> limits - and these should be properly marked-up

> with regular speed limit reminders (I have posted

> elsewhere on the 'Rapel' system used in e.g.

> France to remind people of the limits). I think

> (and I live in it) that Underhill is all 20mph -

> but it is not always clear - and I am regularly

> hooted at, when going at or just below 20, by

> drivers who either don't know, or don't care, and

> wish me either to speed up or to let them

> over-take.

>

> In many places weight of traffic and of parking

> mean that 20mph or less is often the only safe

> speed to go at (sometimes the only possible speed

> to go at) outwith any formally set limits.

>

> I would be happy for the whole of Dulwich and ED

> south of Goose Green and bounded by the S Circular

> to be 20mph as a broad zone, properly marked-up,

> but odd roads and half roads make no sense and

> will simply confuse.

>

> I suspect, based on other posts, that Mr Barber is

> mixing it with fellow councillors in another ward

> and is using this 'genuine question' as a

> political stalking horse. His right, of course, as

> party political politician, ours, not to play the

> games with him.

Have to say I agree with this sentiment regarding the political side not the 20 mph broad zone.

[Loz]

StraferJack Wrote:

-------------------------------------------------------

> "If cars are (allegedly) travelling that fast,

> Cora, how would changing the speed limit help?"

>

> I'm guessing that of the "speeders", a large number are % offenders - ie they like to travel

> just above the limit - "that's not really speeding"

>

> So the speed of any such impact would be above a new limit but still significantly reduced

But James' own figures show that at 85% of drivers are travelling at at least 6mph below the speed limit already. And the average speed is already below 20mph. The number of speeding drivers must already be a rather tiny number.

[unlurked]

No to 20mph on MG. As others have stated, vehicles can hardly reach 20 let alone over 30mph! JB you are loading the question again to suit your own views and wishes like you do with certain planning apps, certain retail chains that you like, and anything that is anti car. Try being fair and balanced.

[BrandNewGuy]

Well, if you can hardly get to 20mph, why object to it as a limit? I'd approve of a 20mph limit on all residential roads in towns and cities - 30mph is crazily fast on a residential road with parking on both sides and tight corners at the ends. Our local A roads (Lordship Lane, Grove Vale, East Dulwich Grove and East Dulwich Road) are a different matter, however. I'd stick with a 30mph limit on those, but look to having other 'shared use' traffic calming measures at busy points.

[cwjlawrence]

James,

My view is not the speed limit that is the issue (as people mention, it's difficult to get into double figures!) but the number of cars that are parked along the road especially at the east dulwich grove end of the road. This makes it rather dangerous for pedestrians trying to cross the road and also for cyclists.

What are the rules please on reducing the amount of parking on a road, specifically on the corners? Thanks!

[LalKJ]

With respect d.b., walking down the road twice a day, probably at peak times when traffic is busy and I agree high speeds cannot be reached, is not the same as living on the road, and spending a lot of time at home, and seeing on numerous occasions cars/vans/lorries travelling at excessive speeds (as I think the other posters who actually live on MG agree). I am pleasantly surprised at James' figures provided, perhaps the problem is not the general volume of traffic travelling quickly, but more, because it is seen as a rat run, those that are looking to avoid the traffic and traffic lights down Lordship Lane tend to speed excessivey down our road.

[Loz]

BrandNewGuy Wrote:

-------------------------------------------------------

> Well, if you can hardly get to 20mph, why object to it as a limit?

1) Cost. Adding all the new signs, etc will cost quite a bit of dosh.

2) If there is a problem with traffic, and this isn't the solution, shouldn't we be looking for the solution? (First step: define the problem.)

20mph limit seems to be the default solution for everything at the moment.

[unlurked]

BrandNewGuy Wrote:

-------------------------------------------------------

> Well, if you can hardly get to 20mph, why object

> to it as a limit?

That is a non argument-if you can hardly get to 70mph on, say the M25, why object to 70 as a limit!

Where are the accident stats for MG that support J Barbers wishes? This is just another con to get the gullible to call for a CPZ.

[BrandNewGuy]

What's a CPZ got to do with it? I was one of the loudest objectors to that idea, but would happily see 20mph limit on all Southwark's residential roads. But you like to see a web of conspiracy everywhere.

[ed_pete]

unlurked wrote:

> Where are the accident stats for MG that support J

> Barbers wishes? This is just another con to get

> the gullible to call for a CPZ.

Wow you really don't like JB do you unlurked ?

I thought he was just asking a question, I don't see any wish expressed.

[Burbage]

James Barber Wrote:

-------------------------------------------------------

> Do you think we sohuld make this 20mph?

A lot depends on what that means. If the road is already equipped with the sort of traffic calming measures that the DfT and councils are pleased to think of as 'self-enforcing', then you're just talking signage, in which case you'd get exactly the same effect by making it a Nuclear Free Zone or an Empire of Happiness, either of which would be cheaper (there's less paperwork, and you'd not have to advertise the change in the newspapers).

The magical effects of 20mph zones only work where they're in conjunction with measures that make rat-running more difficult than it was to start with. Drivers, certainly in London, know full well that a 20mph sign means the same as 'no speed cameras' and having won several victories over speed hump heights (and, it seems, universally jacked up their suspensions), won't necessarily slow down on account of them. So now, short of a blanket 20mph zone enforceable (and enforced) by average speed cameras, I can't see incremental additions to an already dubious network being cost-effective. Unless, of course, some serious studies into the effects of them have been carried out since 2006, but I can't find any.

I'll admit that data is not everything. But it is the only difference between a sensible proposal and a futile gamble. Assuming it's presented and interpreted correctly. Cllr Barber has, let's say inadvertently, illustrated this rather neatly by relying on an excerpt that's certainly not the most recent available and making something of an assumption about what's happening in the top 15%.

Looking at all the data that the council has been pleased to let us see at our own expense, the picture is subtly different. It is, by and large, this:

LOCATIONDIRECTIONSTART_DAYMONTHYEARDaily FlowAVE_SPEED_85TH_SPEED

Melbourne Grove northNorth25SEPT2010241616.519.5

Melbourne Grove northSouth25SEPT2010219713.916.8

Melbourne Grove north sectionNorth2JUL2009248618.922.4

Melbourne Grove north sectionSouth2JUL2009221819.023.5

Melbourne Grove south sectionNorth1JUL200990818.222.4

Melbourne Grove south sectionSouth1JUL2009112717.921.7

I am no statistician, but that seems to show a reduction in average speeds between 2009 (the counts Cllr Barber chose) and 2010 (the most recent data they've bothered to collect) and that's at least comparable with the effect you'd expect from declaring a 20mph zone. All achieved, apparently, without having to bother declaring one at all.

I can see that there may be problems with this. The data is a bunch of snapshots taken with equipment we may or may not be able to trust and processed by lurky folk we pay but cannot see, taken at specific times of the year on particular bits of road which may, or may not, have been dug up, used for street parties or full of potholes at the time. In other words, we have no real idea which bits of it might reflect reality and thus, for all my presumptuous sniping, what I think I see might be just as wrong as what Cllr Barber thinks he sees.

So the question is, do we believe the data, which clearly shows no need for a 20mph zone, or disbelieve it, leaving ourselves with not data to support one? It's tricky. Though it's also a fine demonstration of how, provided they're careful to publish sufficiently fragmented and questionable data, councils get to do whatever they like.

Morally, the right thing to do is whatever TfL doesn't. That, in this case, would mean either collecting recent, reliable speed data (rather than just counting vehicles). Or, if you can't be bothered to do that, asking the people who live along the road. After all, although it's the public highway, the residents are members of the public, and a lot more likely to use the road than anybody else. Admittedly, they do so disproportionately for pedestrian purposes, but there really is no moral reason why the council should treat pedestrians with the utter and brutal contempt that it usually affords them, and a change is always pleasant.