20 mph limit?

[KidKruger]

KidKruger Wrote:

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> A 20mph restriction makes roads for drivers and

> pedestrians safer.

Says who?

Says me.

As a driver, pedestrian and cyclist.

I pulled-over a moped guy last night for going too fast on CP Rd, it?s s 20mph zone and he was taking the piss with his speed.

Bizarrely he agreed, and apologised !

[Sally Eva]

KidKruger Wrote:

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

> KidKruger Wrote:

> --------------------------------------------------

> -----

> > A 20mph restriction makes roads for drivers and

>

> > pedestrians safer.

>

> Says who?

>

> Says me.

> As a driver, pedestrian and cyclist.

> I pulled-over a moped guy last night for going too

> fast on CP Rd, it?s s 20mph zone and he was taking

> the piss with his speed.

> Bizarrely he agreed, and apologised !

This can be an enjoyable occupation carried out under police protection. It's called Community Speedwatch and is organised jointly by the Met, TfL and members of the community (ie you and/or ANO).

You (the volunteer or ANO) is trained to use a speedgun. You have to wear hi-vis and stand in a prominent position (must give these speeders a chance) and then call out the numbers you see on the gun to the policeman who writes them down with the make and registration no of the vehicle.

Drivers then get rude letters about the calibre of their driving and warnings to improve it.

To join in email [email protected]. His photo is attached. He's a very nice, affable guy with a strong desire to protect the elderly, vulnerable and children by improving standards on the roads.

[spider69]

Do they do the same procedure to cyclists or are they exempt?

[Asset]

*sigh*

[Penguin68]

Do they do the same procedure to cyclists or are they exempt?

Cyclists carry no marks of identity to allow any follow-up. Perhaps more relevant - do they also follow up on buses which speed - I have certainly seen some on Barry managing quite a lick, considering that they have lights and stops to hold them up.

[DulwichLondoner]

KidKruger Wrote:

> > A 20mph restriction makes roads for drivers and

>

> > pedestrians safer.

>

> Says who?

>

> Says me.

> As a driver, pedestrian and cyclist.

It's hard to argue with such a well-explained argument. But let me try...

The Department for Transport commissioned a long study into 20mph limits. The results were published about 6 months ago.

First of all, why did so many councils rush to introduce 20mph limits BEFORE this study was concluded?

It's hard to shake off the suspicion they thought the study would not support the new limits, so they wanted to introduce them first - because by now it would be very messy and expensive to remove them.

In summary, the study says that it is INCONCLUSIVE whether 20mph limits really make roads safer. There was a reduction in one case (Brighton), but in all other cases the results were inconclusive. There are also lots of caveats about extrapolating the Brighton results more generally

Don't take my word for it - go to the source:

https://www.gov.uk/government/publications/20-mph-speed-limits-on-roads

Page 66 of the headline report:

? This study has found no significant safety outcome (in terms of

collisions and casualties) in residential areas, based on the post implementation data available to date. Due

to the small sample sizes and variability in the data, the statistical analysis undertaken to date indicates that

the real change could be positive or negative. In addition, it has not been possible to draw any conclusions

regarding the relative change in fatal injuries, cycle casualties, and casualties involving older people.

In the case of both the residential and city centre case studies, further data is required to determine the longterm impact of 20mph limits. Collision and casualty rates are known to fluctuate from year to year, and the

post implementation data currently available may not be indicative of the longer-term trend.

[Penguin68]

...So, the jury is still out. However I think there are no doubts that impacts on pedestrians or cyclists at 20mph are likely to be less severe than at 30mph. Physics alone demonstrates that. [Older vehicles with less forgiving construction - less 'crumple zone' - will of course always be more injurious than modern vehicles, at any given speed.] Additionally a slower moving vehicle logically must give greater decision time to others using the road.

So I have no problems in believing that a 20mph limit is likely (everything else being equal, which it rarely is) and if adhered to to be making a positive contribution to road safety, if measured in the severity and possibly frequency of accidents.

[DulwichLondoner]

Penguin68 Wrote:

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> ...So, the jury is still out. However I think

> there are no doubts that impacts on pedestrians or

> cyclists at 20mph are likely to be less severe

> than at 30mph.

Of course, that is self-evident. It is also not the whole story.

Is there any downside? E.g. is it an incentive for pedestrians to cross dangerously in the middle of the road, even if there is a traffic light 100 yards away (or precisely because there is one and they don't want to wait)?

How much does the introduction of 20mph limits cost? How else could this money have been spent? I think Lambeth or Southwark spent something like ?700-800k. How many potholes could have been fixed? How many injuries (especially of cyclists) are instead caused by potholes?

Etc etc etc.

No such assessment was ever done. There was an ideological drive to push the 20mph limits, with no kind of cost benefit analysis.

Also, what is the environmental impact of travelling at 20mph vs 30? At rush hour probably not much, but outside rush hour, at night, etc? I genuinely do not know. The report says that another study is being done and will be completed around 2020.

I am very worried when ideology trumps facts.

At the very least we should acknowledge that the jury is still out, and that all the claims made by the councils about the "clear benefits" were all bull**** - nothing is clear, in fact.

Similar story for cycle superhighways: where's the cost benefit analysis?

The Transport watchdog complained they would increase journey times for busses, but was ignored. Detractors claims the cycle lanes are empty outside of the 7.30 - 9.30 am peak time, but cause congestion the rest of the day (especially where bus lanes were removed to make way for them).

This is my impression, too, but I don't know for sure. Why didn't TFL monitor usage throughout the day before rolling out new cycle superhighways? It would not have been particularly difficult nor expensive.

[exdulwicher]

Do they do the same procedure to cyclists or are they exempt?

Speed limits don't apply to cyclists (or horse drawn vehicles) because they're not legally obliged to carry any form of speedometer and (although plenty of cyclists have computers fitted) there's no nationally approved calibration test for them.

They can however be done for reckless or dangerous cycling. The fines are usually orders of magnitude higher than for drivers...

Similar story for cycle superhighways: where's the cost benefit analysis?

The Transport watchdog complained they would increase journey times for busses, but was ignored. Detractors claims the cycle lanes are empty outside of the 7.30 - 9.30 am peak time, but cause congestion the rest of the day (especially where bus lanes were removed to make way for them).

This is my impression, too, but I don't know for sure. Why didn't TFL monitor usage throughout the day before rolling out new cycle superhighways? It would not have been particularly difficult nor expensive.

You don't count the number of people swimming across the river before you decide whether or not to build a bridge over it - it's fairly self evident that building a bridge will lead to more people crossing the river.

As a rough general rule, efficient transport systems often look empty. But no-one looks up and down the train tracks and says "i can't see any trains but the road alongside it is gridlocked, we hould rip up the tracks and replace it with extra highway".

Cycle lanes often look empty compared to a road becasue cyclists are smaller than cars and because they move far more efficiently, they just flow better. Therefore the system looks quieter. It isn't - it's actually moving more people than the neighbouring vehicle lanes. The stats across Blackfriars and along Embankment bear this out, about 70% of the people movements (note PEOPLE, not VEHICLES) is pedestrian and cyclist at peak times yet the pavements and bike lanes don't look as busy as the carriageway. Just means that vehicles are woefully inefficient and the answer is absolutely not to build more highway, it's to enable people (again PEOPLE, not CARS) travel more efficiently.

And in terms of cost benefit - cycle lanes are ? for ? the most efficient and best value thing a city can build:

https://www.cyclinguk.org/campaigning/views-and-briefings/cycling-and-economy

That's obviously a cycle campaigning organisation but the figures are borne out from various studies in various countries. Denmark, The Netherlands, there's one from Pilsen (Czech Republic) and a couple from cities in America if you search online.

[DulwichLondoner]

exdulwicher Wrote:

> You don't count the number of people swimming

> across the river before you decide whether or not

> to build a bridge over it - it's fairly self

> evident that building a bridge will lead to more

> people crossing the river.

Totally irrelevant comparison. Cycle lanes are not about building new roads instead of unused land. They are about diverting existing roads away from buses (remember, many bus lanes were removed!) and other road users to make way for bicycles.

> As a rough general rule, efficient transport

> systems often look empty.

Even at traffic lights?

> Cycle lanes often look empty compared to a road

> becasue cyclists are smaller than cars and because

> they move far more efficiently, they just flow

> better.

> Therefore the system looks quieter.

I can tell the difference between heavily used cycle lanes during rush hour, and mostly deserted cycle lanes outside of rush hour.

How many passengers fit on a double decker bus? 80 to 90? How much space is occupied by a double decker bus vs by 90 pushbikes? Removing bus lanes to make way for cycle lanes means more congestion and more pollution. That's idiotic!

> about 70% of the people movements (note PEOPLE,

> not VEHICLES) is pedestrian and cyclist at peak

> times yet the pavements and bike lanes don't look

> as busy as the carriageway.

Another totally irrelevant comparison. Start by taking pedestrians out of the equation. They have nothing to do with this. The point is: what is the best use of the limited road space we have? Is it cycle lanes or not?

You see, I am not saying that I know for certain that cycle lanes are a bad use of that space. I get that impression, but I don't know for certain. My point is that, before rolling out more and more cycle lanes, this should have been measured, both during and outside rush hour. It wouldn't have been hard to do, yet it wasn't done. Why???

>

> And in terms of cost benefit - cycle lanes are ?

> for ? the most efficient and best value thing a

> city can build:

> https://www.cyclinguk.org/campaigning/views-and-br

> iefings/cycling-and-economy

What a load of unsubstantiated nonsense... Have you read that link? Strenghtening local economies, supporting property values, enabling disadvantaged groups to gain skills and access employment opportunities... Anything else? Will cycling beat cancer, too? Most of all, where's the proof? Some data, something, anything?

I skimmed through the PDF linked on that page. You cannot comapre Copenaghen to London. London has more people than the whole of Denmark!!

These cycle lobbies were also the same that told us that 20mph is safer. Guess what, the DfT report doesn't say that, it says the data is inconclusive! These lobbies were also the same that complained heavily against the use of the stickers "cyclists and motorcyclists stay back" because they were deemed offensive, so you will forgive me if I don't deem them particularly sensible nor reliable. Disclaimer: as a motorcyclist, "stay back" is what I do out of self-preservation!

I repeat, the Transport Watchdog expressed big reservations against cycle lanes because it was worried on the impact it would have had on public transport. Of course the cycle lobbies totally ignore this point.

Cycle lobbies forget a couple of key, crucial points. I am all for disincentivising private car use. But, honestly, between congestion charge fees and the cost of parking, how many people drive to work into central London? The point is that there are a number of vechicles which are simply necessary: buses delivery vans construction vehicles tradesmen's vans etc. Even in the greenest city ever, these cannot be replaced by bikes. Also, London is so huge that a number of east to west or north to south routes MUST pass by the centre - a problem which smaller, more cycle friendly cities like Amsterdam or Valencia do not have.

[renard]

> Page 66 of the headline report:

> ? This study has found no significant safety

> outcome (in terms of

> collisions and casualties) in residential areas,

> based on the post implementation data available to

> date. Due

> to the small sample sizes and variability in the

> data, the statistical analysis undertaken to date

> indicates that

> the real change could be positive or negative. In

> addition, it has not been possible to draw any

> conclusions

> regarding the relative change in fatal injuries,

> cycle casualties, and casualties involving older

> people.

> In the case of both the residential and city

> centre case studies, further data is required to

> determine the longterm impact of 20mph limits.

> Collision and casualty rates are known to

> fluctuate from year to year, and the

> post implementation data currently available may

> not be indicative of the longer-term trend.

This particular study couldn't give any conclusive evidence because of lack of data and also because the vast majority of drivers were not respecting that limit anyway on the 20mph zones (86% of them!).

It's a report on the impact of their implementations in these area (the 20mph signposts)- it's not a safety study of the actual speed (of course 20mph is safer!).

Personally I think it's probably time to enforce these limits more strictly.

[DulwichLondoner]

renard Wrote:

> It's a report on the impact of their

> implementations in these area (the 20mph

> signposts)-

Of course - that's the whole point of the study!

>it's not a safety study of the actual

> speed (of course 20mph is safer!).

Yes, that is banally self-evident. It is also NOT the point. Yes, being hit at 20mph is better than being hit at 30mph. And being hit at 10 is better than being hit at 20. So where do we set the limit and why? 10? 15? 20? 25? 30?

The answer to this question should be based on a study like the DfT's one, which looks at the situation as a whole.

How many accidents are caused by speeds > 30mph? Clearly all the accidents caused by drunk driving, by cars reversing, or any low-speed accident would not be affected by the speed limit.

What are the key factors determining accidents? Is it just speed? Road quality (eg potholes)? Road layout?

Are there any downsides to 20mph limits?

Are pedestrians incentivised to cross like suicidal idiots if the limit is 20mph?

What is the environmental impact of cars going slower and journeys taking longer (at least outside of rush hour)? A study on this is underway and should be completed next year, as the DfT report mentions.

How much does it cost to introduce 20mph limits? How else could that money have been spent and which is the best use of that money?

I do not have the answers to all these questions. But I think we need them before deciding what to do. Otherwise it's just blind ideology with no connection whatsoever to facts and evidence.

[exdulwicher]

What is the environmental impact of cars going slower and journeys taking longer (at least outside of rush hour)? A study on this is underway and should be completed next year, as the DfT report mentions.

A few factors:

More than half of all car trips are under 5 miles:

https://www.licencebureau.co.uk/wp-content/uploads/road-use-statistics.pdf

So taking that into account and doing some basic distance / speed / time calculations:

1 mile at 20mph: 3 mins

1 mile at 30mph: 2 mins

2 miles at 20mph: 6 mins

2 miles at 30mph: 4 mins

3 miles at 20mph: 9 mins

3 miles at 30mph: 6 mins

4 miles at 20mph: 12 mins

4 miles at 30mph: 8 mins

So over a 4 miles journey driven at a steady 20mph, you'll take 4 minutes longer than doing the exact same journey at a steady 30mph. But that's never the whole story because no journey is ever done like that. Junctions, traffic, road layout etc all mean that you're never cruising at a steady 20 (or 30), it's constantly up and down between zero (at traffic lights for example) and the maximum (assuming for a moment that we're all model drivers that never break the speed limit!) and the actual time spent near the maximum is often very low.

I don't have any data for it but I'd hazard a guess that in real-world conditions, the actual time taken on an urban journey is actually very similar no matter what the maximum speed limit is. Be interesting to come up with a few journeys of (say) 3 miles and try driving them. Two vehicles leaving at the same time, one never exceeding 20mph, one never exceeding 30mph. See what the actual difference in time is at the destination.

[DulwichLondoner]

The fact that the average journey is short is a technically true but practically often irrelevant piece of information the cycle lobby loves to spit out whenever it can, typically to claim that more people should use pushbikes and that therefore more road space should be given to bikes. That?s total complete utter nonsense. A TFL report on the topic also said that, surprise surprise, both car ownership and car usage were much lower in inner vs outer London.

If you live in certain parts of zones 3-6, or of Surrey/Kent, just inside or just outside the M25, you often need the car even only to go to the supermarket, or to take kids to school, or to go to the train station. You often don?t have an alternative. If you live in zone 1 and take the car everywhere, by all means, that kind of use should be penalised, but just looking at the average journey, as if it were representative, is totally misleading.

Back to your point. First of all I said from the beginning that, at rush hour, I would expect 20mph limits to make little to no difference. You seem to focus on the little inconvenience that would probably derive from lower limits. I was trying to focus on the environmental impact. Yes, if our journeys only take a few minutes more it?s not the end of the world. But how much is that in %? If every journey outside of rush hour takes, say, 20-30% longer, that?s car engines being on and polluting for 20-30% more time. What is the environmental impact of that? I do not know, but I think this point should have been addressed before rolling out 20mph limits eft right and centre. Sadly, it wasn?t.

The inconvenience is probably for those drivers that need to drive, outside rush hour, longer-than-average routes that must pass through the centre of London, e.g. many east to west or south to north routes. Think of all kinds of vans, delivery vehicles, HGVs, etc. I am not of these drivers, but, if I were, I?d be furious.

[exdulwicher]

I wasn't making any claim on that at all, my post was solely about journey times. You can find the stat about car usage / journey lengths from the Office of National Statistics.

I'm not "cycle lobby". I walk, ride a bike (my own and Santander Cycles), I use trains, Underground and buses and I own and drive a car. I just pick whichever method happens to be most convenient and appropriate for the time and place. I'm just in favour of people getting around efficiently. If it can be done in ways that minimise pollution and danger then so much the better.

As per my last paragraph, I would be genuinely interested in seeing some real-world data about the differences in time it actually takes to do an average urban journey around East Dulwich with a max speed of 20 and a max of 30. If there was a relatively convenient way of measuring pollution during that time, that would make the test even more useful.

[DulwichLondoner]

So you are in favour of 20mph limits even though you have no idea:

if they really reduce accidents (the DfT report says the evidence is inconclusive)

what the environmental impact of longer journeys is

if that money could have been spent elsewhere (eg improving roads / potholes /new road layouts).

Remind me, then, WHY are you in favour of the 20mph limits?? What's your thought process?

[exdulwicher]

DulwichLondoner Wrote:

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> Remind me, then, WHY are you in favour of the

> 20mph limits?? What's your thought process?

At no point in any of the previous 3 pages have I specifically said "I am in favour of them". I've highlighted some of the (alleged) positives behind them, linked to some reports - one of which specifically mentions that putting them in is largely pointless since about 80% of drivers routinely ignore/flaunt the limit) and pointed out a couple of times the fact that 20mph zones are rarely put in as a single item.

Done well, they should be done in conjunction with other measures like closing off rat-runs, making parking residents only and so on.

Same things with ASL (the advanced stop lines for bicycles). Done well, they incorporate advance lights for bicycles (like at the junction of Greendale / East Dulwich Grove / Townley Road). Done badly, it's just a strip of paint that puts bicycles at front of an F1 starting grid of impatient drivers...

I'm in favour of transport schemes being done well. A half arsed system does no-one any favours. I can see the positive arguments for 20mph. I can see the limitations (like trying to do it without enforcement where pretty much everyone ignores it).

If you look on the thread about a proposed pedestrian crossing at Harvester / South Circ junction, you'll see reports of routine red light running by drivers. That's another example of a traffic scheme done badly. I think we're all in favour of traffic lights but I also think we all get frustrated at badly planned set-ups - those ones with a fleetingly short green light or ones where you sit there for ages while empty lanes get green lights. And therefore you get non-compliance, complaints etc (slight digression to make the point).

But at no point did I say "I am in favour of 20mph zones, East Dulwich should have them everywhere". I do like the discussion though, it's raised interesting points on both sides including yours about increased time on the roads. And again, I'm happy to state that I have no idea of the effect - it would be very interesting to conduct some tests though.

Cheers

[DulwichLondoner]

exdulwicher Wrote:

>

> At no point in any of the previous 3 pages have I

> specifically said "I am in favour of them".

exdulwicher, I confused you with the other user who replied "says me". I apologise!

[ashleywlkr]

I was very nearly injured yesterday when a BMW sped past my drive as I was pulling out in my car. he was travelling in excess of 50/60mph.

I live on lordship lane, between the lordship and the plough pubs, busses, cars, lorries, all vehicles speed on that part of the road.... it's only a matter of time before someone it seriously injured.

Speed cameras/average speed checks ought to be put in place. sped calming measures, such as speed bumps, and other things, I think should probably be resorted to if all else fails, as they are mostly disruptive, and on the wobbly ground will make houses shake.

[DulwichLondoner]

ashleywlkr Wrote:

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> I was very nearly injured yesterday when a BMW

> sped past my drive as I was pulling out in my car.

> he was travelling in excess of 50/60mph.

Sorry to hear that. However, that has little to do with 20 mph. A reckless driver will continue to be reckless regardless of speed limits.

In fact, the most sensible argument I can think of for 20mph limits is that, maybe, with 30mph limits many people may speed up to 4, so with 20mph many people may speed up to 30...

What is the tolerance for speed tickets? On many analog speedometers it is virtually impossible to distinguish 20 vs, say, 22 mph; would 22 mph in a 20 zone mean a ticket? Possibly points on the licence?

[exdulwicher]

DulwichLondoner Wrote:

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

> exdulwicher Wrote:

> >

> > At no point in any of the previous 3 pages have

> I

> > specifically said "I am in favour of them".

>

> exdulwicher, I confused you with the other user

> who replied "says me". I apologise!

No probs @DulwichLondoner!

Also, look what I found:

https://movement.uber.com/explore/london/speeds/query?lang=en-GB&dt[tpb]=ALL_DAY&dt[wd;]=1,2,3,4,5,6,7&dt[dr][sd]=2018-01-01&dt[dr][ed]=2018-01-31&ff=

That's a speed map of Uber journeys - you can choose a city, choose a date range and the info you want to see (I've selected Average Speed) and then just hover the mouse over a road and it shows you average speeds for certain times of day 9again, selectable). Not really had time for a full play around with it but it's certianly got info around East Dulwich. tells you how much of the journey was free-flow and how much was heavy traffic.

[DulwichLondoner]

That's interesting. I have, in fact, often wondered if we have too many minicabs, and if reducing the number wouldn't improve congestion and pollution, especially in zone 1. Minicabs are currently exempt from the congestion charge - whereas in fact they should pay a much higher congestion charge than an ordinary car, I'd think.

[Earl Aelfheah]

Electric Uber bikes now operating in London (but not in SE London / Southwark obvs).

[exdulwicher]

https://www.bbc.co.uk/news/uk-england-london-48524152

News item about TfL's consultation on a plan to roll out 20mph across TfL-managed roads in London over the next few years.

[jonnywalker]

Fact is nobody really cares about the 20mph limit as the police never enforce it. If you drive at 20mph anywhere in London including Southwark you have cars inches from the rear trying to pressure you into going faster. EVERY bus that goes past our house - 343 484 P12 goes way in excess of 30mph down tight residential streets completely ignoring the speed limit. I've been on buses and asked the driver to slow down only to be arrogantly dismissed. If TFL are to introduce this limit London wide then hopefully they'll put limiters on their buses.