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FAO anyone who supports the 20mph limits..







GT49er

Well-known member
Feb 1, 2009
46,800
Gloucester
Glad I attended one, completly changed the way I drive now

After 42 years of driving, with a clean licence and insurance record, I had to do a speed awareness course. Two months later I had my first ever traffic accident (fortunately only a very minor one), on a roundabout.

I don't think they're all they're cracked up to be...............
 


The Fifth Column

Retired ex-cop
Nov 30, 2010
4,029
Escaped from Corruption
Notters, I've also noticed that slower traffic speeds mean that there is less congestion at crucial pinch points. The faster you travel the more vehicles you get from one pinch point to the next. While your argument that there is more pollution from a car doing 20 than 30, there is far more pollution from toe to tail queuing traffic. If slowing traffic down reduces the flow of traffic between pinch points thereby reducing the numbers of queuing traffic, your argument is dead in the water.

As for people naturally driving sensibly in residential streets - depends on the street. If its a cut through like Hallyburton Road avoiding the rail crossing on Boundary Road, then people fly up there. That has changed to 20mph, and while the majority probably still average around 30 or just under, it has greatly reduced the number flying up there at 35 mph+ - therefore the 20mph zone has done it's job in my opinion.

I agree Old Shoreham Road should probably stay a 30, but that said, it's still treated as 40mph, even though as far back as Southwick to Hove Rec. it is a 30mph limit. Drive along there at 30mph and you will be overtaken by everyone. You'll be overtaken by most even if you're doing 35mph. Perhaps enforcement is the issue there rather than further reducing the speed limit.

I got pinged by a mobile camera on the Old Shoreham Road by the cemetary, I was doing 38mph. There were a few cars in front of me and a few behind and we were all doing the same speed, that poxy camera must be making a fortune! Considering the same dual carriageway turns into a 40mph limit a bit further west where it is bordered by houses I felt it was a bit harsh. Oh well, I will be attending my speed awareness course next week for 4 hours education, better than 3 points I suppose.
 


Bold Seagull

strong and stable with me, or...
Mar 18, 2010
29,832
Hove
I got pinged by a mobile camera on the Old Shoreham Road by the cemetary, I was doing 38mph. There were a few cars in front of me and a few behind and we were all doing the same speed, that poxy camera must be making a fortune! Considering the same dual carriageway turns into a 40mph limit a bit further west where it is bordered by houses I felt it was a bit harsh. Oh well, I will be attending my speed awareness course next week for 4 hours education, better than 3 points I suppose.

I think it is 30mph till you get past the main junction with Locks Hill, so you still had a long way to go before you got to the 40 zone. That mobile van is often there, and sat on the brow of the hill just at the apex of the bend opposite Olive Road I expect does catch quite a few out. It does both East and West bound traffic from that spot. You have kind of proved my point above though.

I can't plead innocence as I got caught doing 80 down the A23 a few years back and also did the speed awareness course. Just go with an open mind, I thought it was a really interesting, well presented morning that did, as others have said, have an impact on my thought processes when I drive. It isn't the condescending telling off session people expect.
 


Notters

Well-known member
Oct 20, 2003
24,869
Guiseley
Couple of last questions from me (knowing you're busy!)

When you say next to a main road, do you mean directly adjacent to a main road? How close is too close?

No worries. When we do an assessment, we look at the sum of background pollution concentrations (which vary across the country and are essentially a result of the mixing of pollutants in the atmosphere), and add to that the pollution from traffic at a particular point. The pollution at any point is therefore calculated (using a dispersion model) based on traffic volumes and speeds, background pollution, meteorological data, etc.

So to answer your question, it's not that simple. But pollutant concentrations drop off rapidly with distance from roads. I'll try and put together a specific example at some point, perhaps tomorrow. But yes, within a couple of metres of a road pollutant concentrations tend to be particularly high.

If you look at Brighton & Hove City Council's progress report, you can see the areas that they're particularly concerned about on Page 13:http://www.brighton-hove.gov.uk/sit...r Quality Progress Report 2014 (PDF 3 MB).pdf

Also are there any decent online resources to read up further on this stuff - whilst avoiding the political point scoring on either side? Cheers

There are lots, it depends on the level of detail you want to go into really. The EPUK (who were based in Brighton) guidance gives a reasonable sort of overview, in terms of the planning issues http://www.iaqm.co.uk/text/guidance/epuk/aq_guidance.pdf . Defra also provide a lot of information, although a lot of it is very technical http://uk-air.defra.gov.uk/. Let me know if any other questions.
 




Machiavelli

Well-known member
Oct 11, 2013
16,678
Fiveways
Feel free to pm me. I'm in favour of the 20 mph limit.

Me too.
Perhaps [MENTION=5200]Buzzer[/MENTION] can have a look at this thread (I've only had a look at the first page), as he at one point claimed that no-one/very few are in favour of it.
We have a Green council to thank for it too, alongside numerous measures to improve the experience of pedestrians and cyclists. They haven't got everything right, and have extended 20mph (and, even in some cases, 30mph) too far at times but, on the whole, it's an improvement.
ps I say this as someone who walks (or limps at present), cycles, uses a bus, train and occasional taxi and now owns but irregularly drives a car. I try not to fly, although work occasionally means I have to (although this is only two return journeys in a decade).
 


Stat Brother

Well-known member
NSC Patron
Jul 11, 2003
73,869
West west west Sussex
The only problem with a 20 mph limit is...





...I'll have slow down on my bicycle :p :blush: :yawn:
 


Jul 24, 2003
2,289
Newbury, Berkshire.
I've got no problem with the 20mph limits for safety reasons, but what did really really piss me off was the bollocks claim that it 'improved air quality'. No it didn't, it was a trade-off as the people of Storrington* found. Thank you Notters for finally nailing that lie. No chance of ***** like Davey recanting though.


*Storrington residents were worried about vehicle speed through the town centre so they introduced methods of slowing it down. The result was that that the air quality deteriorated badly.

But that is because the average car, with the average engine and gearbox, is designed to be at it's MOST efficient revs at the statutory speed limit of 30-40mph in 3rd/4th gear, and 60-70mph in 5th gear.

In a 20 mph zone, air quality can be improved by sophistcated engine management shutting cylinders down, as you simply don't need such a high engine capacity to maintain a lower speed. Or you can stay in 2nd gear to maintain 20mph, maintaining revs at the most efficient setting.

However, forget the internal combustion engine, the future for urban motoring (especially buses and delivery vehicles) is electric ( be it all electric or hybrid ).
 
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symyjym

Banned
Nov 2, 2009
13,138
Brighton / Hove actually
You're right to point out that the issue is far more complicated than I've made out. We can only do so much to model for people's driving style. The important thing to realise is that it's the main arterial routes with large flows of traffic that are the issue, as these are the only places where exceedences of the the National Air Quality Objectives (http://uk-air.defra.gov.uk/assets/documents/National_air_quality_objectives.pdf) are likely to occur at sensitive receptors (i.e. houses). In particular (for Brighton), Preston Road, Ditchling Road, Old Shoreham Road, Davigdor Road etc. It is the long term (annual average) pollutant concentrations that are the issue and therefore long term (annual average) traffic speeds which generally matter. I would argue that these routes, at least, should remain at 30mph. People will naturally (apart from a few idiots) drive slower on smaller residential streets with lots of parked cars anyway.

Not really sure about Preston Road, Ditchling Road or Davigdor Road mainly for the consideration of pedestrians. Seafront Kings Road, Old Shoreham Road and New Church Road should be 30mph though.

I think the biggest pollutant cause in traffic are traffic lights because they impose stopping even when the road is clear. In many cases roundabouts are better for the environment. An example of where roundabouts would work well would be all the way down Sackville Road on the Portland Road, Blatchington Road,Church Road and seafront junctions. Maybe even include a mini roundabout at the Clarendon Road juncion.
 


studio150

Well-known member
Jul 30, 2011
29,653
On the Border
I got pinged by a mobile camera on the Old Shoreham Road by the cemetary, I was doing 38mph. There were a few cars in front of me and a few behind and we were all doing the same speed, that poxy camera must be making a fortune! Considering the same dual carriageway turns into a 40mph limit a bit further west where it is bordered by houses I felt it was a bit harsh. Oh well, I will be attending my speed awareness course next week for 4 hours education, better than 3 points I suppose.

The section from the cemetery to the locks hill used to be 40 but was brought down for safety reasons some years ago. I haver seen any merit in that given the dual carriageway and lack of children crossing the road there.
 


symyjym

Banned
Nov 2, 2009
13,138
Brighton / Hove actually
I got pinged by a mobile camera on the Old Shoreham Road by the cemetary, I was doing 38mph. There were a few cars in front of me and a few behind and we were all doing the same speed, that poxy camera must be making a fortune! Considering the same dual carriageway turns into a 40mph limit a bit further west where it is bordered by houses I felt it was a bit harsh. Oh well, I will be attending my speed awareness course next week for 4 hours education, better than 3 points I suppose.

Lot's of people have died along that stretch of road, no pun intended. The speed limit was 40mph, many drove 50mph or more, and if you were trying to join the road from Olive Road you had to nail it, especially if you had to turn first right. I am pretty sure that since the change to 30mph, Olive Road clears quicker.
 




Bold Seagull

strong and stable with me, or...
Mar 18, 2010
29,832
Hove
The section from the cemetery to the locks hill used to be 40 but was brought down for safety reasons some years ago. I haver seen any merit in that given the dual carriageway and lack of children crossing the road there.

I think the merit is that busy junctions like Olive Road had traffic queuing down to Portland Road because vehicles travelling at 40 and above were largely unseen coming from the cemetery making it very difficult to get out onto Old Shoreham Road. This was probably also true of East bound traffic reaching the bottom of the hill where the fire station road is and approaching Holmes Avenue at 40mph+.

By slowing the traffic down, it has made getting out of this adjoining roads (including Stapley opposite Olive Road) much safer and easier to negotiate. Drivers haven't lost anything, they just get to the next traffic light queue 30 seconds slower that they used to.
 


Bold Seagull

strong and stable with me, or...
Mar 18, 2010
29,832
Hove
Lot's of people have died along that stretch of road, no pun intended. The speed limit was 40mph, many drove 50mph or more, and if you were trying to join the road from Olive Road you had to nail it, especially if you had to turn first right. I am pretty sure that since the change to 30mph, Olive Road clears quicker.


Ha ha beat me to it! Had a big impact on all the adjoining roads - totally agree.
 










Stat Brother

Well-known member
NSC Patron
Jul 11, 2003
73,869
West west west Sussex
There's only 59 fixed cameras, 94 mobile cameras & 27 red-light cameras in Sussex.

It's quite some process to have a fixed camera installed, and a lot of the recommendation comes down to 'how many fatalities'.
 






Machiavelli

Well-known member
Oct 11, 2013
16,678
Fiveways
This isn't strictly true. It was being rolled out through the country and was already planned for Brighton before the Greens took office. Some look to it as an excuse to attack the Greens, and the Greens use it to take the plaudits. Both are inaccurate.

Corrected. Stand. I.
ps as you're such a know-it-all on this, do you know whether it was in the local manifesto for the Tories and Labour in 2011?
 


symyjym

Banned
Nov 2, 2009
13,138
Brighton / Hove actually
Corrected. Stand. I.
ps as you're such a know-it-all on this, do you know whether it was in the local manifesto for the Tories and Labour in 2011?

Ok clever cloggs :lolol:

20mph zones started at least 15 years ago in London and pilot schemes were slowly being introduced all around the country. It was always going to happen, and it would have looked daft on the Greens if they didn’t consider it. If we were the first city to change, then I would give the Greens credit for it, but it wasn't their invention.
 


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