Road Safety News

City of London Corporation approves 20mph limit for all roads

Thursday 12th September 2013

The City of London Corporation has approved a plan to reduce the speed limit to 20mph on all roads, as part of its "Road Danger Reduction Plan" which it believes will reduce casualties by almost 10%.

The move is supported by the Mayor of London, TfL, and the City of London Police. City of London Corporation estimates that it will add only minutes to journey times, while benefitting pedestrians "significantly", and with "minimal impact" on air quality.  The Corporation also says the move will further improve cycling safety in the City.

All the surrounding City boroughs, with the exception of Westminster, have already adopted a 20mph limit, which the Corporation says has "been shown to be effective in reducing both the number and severity of collisions".

Mark Boleat, chairman of policy and resources, said: “As an international business hub, the City plays host to a large number of commuters every day.  Steps that make it safer for City workers and reduce the number of tragic deaths are to be welcomed.”

Michael Welbank, chairman of the planning & transportation sommittee, said: “The City of London’s street usage has changed dramatically over the last 10 years, with the number of cyclists tripling. 

"The Corporation has adopted a Road Danger Reduction Plan containing a wide range of measures. The 20 mph speed limit for the City is not the panacea but a further step in reducing casualties.”

The 20's Plenty for Us campaign group welcomed the decision and said it "sends a huge message to London and other global prioritising road safety".

Jeremy Leach, 20’s Plenty for Us London co-ordinator, said: “The City of London joins Paris and Tokyo in recognising that 20mph limits are better for business and health. A quarter of London is now committed to 20mph and other boroughs are watching the City’s decision. More are expected to announce their own borough-wide 20mph limits soon”. 

For more info contact Anna Semlyen, 20's Plenty campaign manager, on 07891 989310.


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Eric: I’m glad you think this evidence is important in establishing the ‘20’s credentials’, but isn’t it a bit late in the day for you to be looking for this? You’ve been opposed to 20s - arguing their effectiveness against reducing accidents for some time - but only now are you asking for specific evidence that they do or they don’t - you should have researched this at the outset. Or perhaps you decided to oppose them first and the evidence was an afterthought?

Anyway, did you mean an actual recorded accident, or an example of what could happen? In any event, I have this niggling feeling you would challenge any examples I provided, or perhaps you were simply testing my memory of 10yrs worth of road accidents! (I recently retired as you may know, so could not access records anyway, even if I was minded to).

But you’re forgetting - I don’t have a problem with these lower speed limits, so I don’t need to waste time looking for evidence of something I already support - it is you who is claiming all along that 20s ‘cause’ accidents which is what I was challenging - so I think the onus is on you to demonstrate this, as I suggested. If at the end of the day you are not able to, so be it – you can’t take it any further and that’s the end of that and we can all move on.
Hugh Jones, Cheshire

Agree (2) | Disagree (3)

Please share one example of a collision/casualty in a 30mph where it would credibly not have happened had a 20mph limit previously been implemented (which is what I asked you to do). This is important in establishing the road safety credentials of the 20mph campaign.
Eric Bridgstock, Independent Road Safety Research, St Albans

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Eric: In answer to your question, yes there are - many! I think you have actually zeroed in on the fundamental problem with this and other accident investigation/ prevention debates here in so far as you and one or two other contributors are concerned, in that, as far as I am aware, you do not have access to individual accident records - only summaries and totals. Whilst that is not your fault, it does mean that your input is going to be limited and presumptions and suppositions will inevitably be made.
Hugh Jones, Cheshire

Agree (3) | Disagree (3)

Hugh, you say: "I, and no doubt lots of readers, see details of actual real-life accidents and get the bigger picture"
Your access to collision and casualty details should enable you to find one (in a 30mph area) where it credibly would not have happened had a 20mph limit been in place.
Without such an example, there is no reason to believe a 20mph limit will prevent any collision/casualty.
Also, your comment about careless pedestrian behaviour over the years conveniently overlooks my comment that they are encouraged to feel safe/safer in 20mph (indeed the assessments questionnaires usually ask if they feel safe/safer, rather than looking at how many have actually been injured).
Eric Bridgstock, Independent Road Safety Research, St Albans

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Actually Eric, the careless pedestrian behaviour you described has always been around - but apparently you've only chosen to notice it recently, whereas those actually involved in accident prevention have always been aware of it, which is why trying to reduce the speeds of the motorised road user in their vicinity is a good idea.
Hugh Jones, Cheshire

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I see the behaviour of pedestrians who have been encouraged (by 20's Plenty and others) to feel safe. Feeling safe is the enemy of being safe.
Eric Bridgstock, Independent Road Safety Research, St Albans

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Eric: As you are well aware, in the spirit of this forum I was being polite and not mentioning any names when I said "seeing what we want to see". You look for the odd kamikazi pedestrian and for you that constitutes evidence of something relating to the speed limit, whereas I, and no doubt lots of readers, see details of actual real-life accidents and get the bigger picture - not just numbers.
Hugh Jones, Cheshire

Agree (9) | Disagree (4)

I agree also that independent and authorative reports are crucial to the debate on 20mph limits. But these do already exist and in most of our comments we reference external material either directly or indirectly in our briefing sheets.

However, when unsubstantiated claims are made on this web site then we feel that they should be challenged. It is the repetition of these claims which results in the repetition of the challenge.

Readers wishing to view the debate from the perspective of a councillor actually making the decision on 20mph limits would be interested in this comment by Cllr Tom Sleigh in the recent City of London debate. See I salute the eloquence and conciseness of his comment.
Rod King, 20's Plenty for Us

Agree (9) | Disagree (5)

Why stop at 20? Why not 10? Could all accidents could be prevented if we stopped everyone moving? Given that the average speed in London is now equivalent to a horse and cart, this signing scheme seems to be nothing but presentation - not substance. Someone is trying to convince us that something is being done. Plastering the City with more unenforced signs will just clutter the streets and make no difference to casualties.
Roger Neal

Agree (6) | Disagree (4)

I fully support and agree with the post by Neil Hopkins, and intend to act on the suggestion he puts forward. There are a number of independent reports in the Knowledge Centre about the effect of 20mph on casualty statistics. I intend to review the evidence and publish a piece in the coming weeks once I have done so. I will invite anyone with an interest in the subject to also forward any independent studies they would like to be included.
Nick Rawlings, editor, Road Safety News

Agree (10) | Disagree (0)

I think that it would be more productive to post links to clearly explained and defined case studies for or against the efficacy or 20mph limits affecting the rate of injury collisions that having this constant to and fro. This impartial hosting and explanation - in terms that the lay-person can understand - could perhaps be facilitated by Road Safety GB.

So far, I am at a total loss to understand how the location of a University affects traffic flows or speeds. and can't quite grasp the unsubstantiated relevance of pedestrian behaviour which I have neither witnessed nor can corroborate.

In my opinion, neither side on the Great 20mph Debate is helping each other, and the continual bickering across public forums with inconsequential information merely helps to denigrate the issue and obfuscate the actual issues involved - all of which relate back to behaviour and nothing else.
Neil Hopkins, Sussex

Agree (13) | Disagree (3)

"Some of us see what we want to see and if we can't see it, we make it up to back up our shaky pre-determined beliefs". Speak for yourself Hugh! I know what I see and what it means for road safety, and I make nothing up. I see the ingredients for increased injuries and that is borne out by the accident statistics in 20mph areas. You carp about others but offer little in the way of proposals, other than compliance enforcement, whatever the cost (financially or in injuries).
Eric Bridgstock, Independent Road Safety Research, St Albans

Agree (3) | Disagree (4)

Some of us see what we want to see and if we can't see it, we make it up to back up our shaky pre-determined beliefs. How are you getting on with the evidence of the actual real-life (not supposition) accidents I mentioned? I take it you've not found it yet?
Hugh Jones, Cheshire

Agree (7) | Disagree (6)

Do you ever look at pedestrian behaviour? My experience of the main street in my home town since 20mph was installed is that they walk into the traffic without looking (often while on mobile), cross pelicans when on green for traffic, etc. Much worse than previous 30mph limit. 'Tis the same in other 20mph areas, in my experience. If you have not witnessed such behaviour, you need to get out more. If you have witnessed it, you are in denial that it is bad for road safety in that it is bound to increase casualties.
Nothing else in the street has changed to cause such behaviour.
Eric Bridgstock, Independent Road Safety Research, St Albans

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If I could just butt in... Eric says: “I have yet to find one scheme where reductions in serious injuries can be attributed to a speed limit change to 20mph”. But it would be more convincing if he could demonstrate how the individual accidents which have occurred in any new 20s – the much vaunted 'increases' - were as a direct result of this lower speed limit (as is erroneously claimed) and not just coincidental.
Hugh Jones, Cheshire

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Once again your willingness to give only part of the story is clear for all to see.
Wikipedia is not authoritative but it will suffice for this: "City University has its main campus in the Islington area of central London, with additional campuses in the City of London and the Holborn, Smithfield and Whitechapel areas of London."

My claims about the effects of 20mph on road safety are based on results from numerous schemes, including the much vaunted Portsmouth disaster. I have yet to find one scheme where reductions in serious injuries can be attributed to a speed limit change to 20mph (an increase seems to be the norm) - would you like to provide one?
And you seem to have overlooked the comparison of the scale of speed reduction versus the scale of time added to the journey. How can 5-10% be more significant than 20%?
Eric Bridgstock, Independent Road Safety Research, St Albans

Agree (6) | Disagree (9)

I will be brief

Eric - I see that City University is actually in the London (20mph) Borough of Islington. An excellent choice if I may say so. Your case seems to keep resting on implications and unsubstantiated claims. Too many “everys” for it to have any grain of credibility.

Brian – The extent to which “human error” causes tragedy can be greatly mitigated by the availability of time and space in order to correct that human error. That’s why speed is implicated in most collisions not being able to be avoided.

Derek – Read the report which I gave the link to. This explains the reasoning of experienced officers within the city who have researched the issues regarding actual speed and collision reduction.

Bobbio – here’s a tactic for speeding taxi drivers “I don’t mind you breaking the law by speeding, if you don’t mind me breaking the law by not paying.” I am not sure what it is in German!

David – Cycles are not motor vehicles and… are. 20mph and 30mph speed limits only apply to motor vehicles.

Dave – There are no speed limits for cycles, so technically they cannot exceed them. But in a compact place like City of London with so many pedestrians it seem ridiculous to legitimise or see any benefit from moving either motor vehicles or cycles around at more than 20mph.
Rod King, 20's Plenty for Us

Agree (10) | Disagree (7)

Transport for London investigated why collisions involving cyclists occurred in London. Their report is in 1.7 here:

One perhaps surprising finding was that almost as many cyclists (24) were "exceeding the speed limit" as motorists (30) (0.75%). It is not illegal for cyclists to exceed speed limits and I would expect many such collisions occur in 20mph areas. Cyclists can easily exceed 30mph though (I certainly can downhill on a good day) so some could occur in 30mph areas.

My fellow cyclists better be careful what we wish for. Widespread 20mph along with accident investigations may lead some to ask: “Should cyclists be required to have speedometers and licence plates in order that they can be prosecuted in the sort of numbers that motorists are?”

Road user groups need to work together, rather than in opposition.
Dave Finney, Slough

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Will the new limits apply to cyclists and motorcycle riders?
David Matthews

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I was recently in Berlin and travelled a lot by taxi. I noticed complete disregard for the 30km/hr limits by my taxis and by nearby vehicles. What is the point of all this expense on 20 limits of they are neither going to be obeyed nor enforced?
Bobbio Chiswell Green

Agree (17) | Disagree (2)

Having used the streets of London as a delivery person for a duration of twenty years and more, I can confirm through personal experience that speeds through the City – a one square mile area – are seldom greater than 25mph at most. There were some exceptions and the greatest was Upper and Lower Thames Street leading to Byward Street; London Wall (much dual carriageway, and barriers preventing pedestrians cheating common sense in the former two, though they still tried), Farringdon Street possibly beneath the Viaduct, and Queen Victoria Street. However, in the latter two instances changes to road layout has almost prevented 30mph being reached save during the early hours.

All other streets through and around the City proper are congested and restricted so severely already, that an impose 20mph limit on all is nothing but an appeasement to government diktat on the assumption that deaths, injuries, and collisions will reduce. They will not, not as long as human beings are what they are and take unnecessary risks when crossing roads and exiting junctions. The statistics will show (if the right ones are sought and assessed) that the vast majority of collisions and accidents occur at speeds below 15mph. These statistics are held by TfL, and are a reflection of those made as far back as seventy years ago when the tram, and horse drawn vehicle were still in abundance.
Derek Reynolds, Salop.

Agree (13) | Disagree (2)

There are obviously some well educated individuals here giving constructed criticism on the effect of a system that is driven by passion rather than common sense. Engineering out a problem of injuries in the City is not the answer and never has been. The Mayor and central government should look more closely at the underlying reason for the majority of collisions which is human error, an issue that can only be solved by education. There is no such thing as a dangerous road.
Brian Chidgey, Bournemouth

Agree (15) | Disagree (3)

As a graduate in Computing, Maths and Stats (at The City University, to boot!) I need no lectures about averages, or about The City. But if you are now saying that those extra 60 seconds would be on a 1.6 mile journey (currently 5 Google minutes) then that is a 20% increase. You may not have said "too small to worry about" but it is implied both by your posting and on your website (where you state "the average urban journey will only take 40 seconds longer"). And for all of this, serious injuries will increase as they have in every other scheme where pedestrians are encouraged to take less care.
Eric Bridgstock, Independent Road Safety Research, St Albans

Agree (10) | Disagree (18)


May I suggest you open Google Maps and type in "City of London". This will inform you of the boundaries of the city. There you will find that the longest journey is about 1.6 miles. Whilst you are on Google, then why not look up the definitions of "maximum" and "average". Then you may understand that reducing the maximum speed in a real world environment with junctions, traffic lights and congestion does not necessarily decrease the average speed by the same amount. You mentioned that I said "too small to worry about". Perhaps you could point out exactly where I said this!
Rod King, Cheshire 20's Plenty for Us

Agree (18) | Disagree (9)

Google maps shows Byward Street to Victoria Embankment to be 3 miles (and 9 min "in current traffic" (20mph). In "free flowing traffic" would suggest that could be therefore completed in less than 9 min. If a 20mph limit adds 1 min, that equates to at least a 10% increase, which is deemed by Rod to be too small to worry about. The Portsmouth 20mph scheme reported average speed reduction of 1.3mph (about 5% of 24mph or 4% of 30mph). So 10% is nothing to get excited about but 4-5% is? We will discuss the more important road safety implications at the Harrogate Conference.
Eric Bridgstock, Independent Road Safety Research, St Albans

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Readers may wish to view the "Benefits and Disbenefits" report prepared by City of London Officers.

This concluded that: "There is little or no disbenefit to introducing a 20mph speed limit and in particular journey-time increases would be minimal given the size of the
City (typically the journey time for the longest route through the City, i.e., from Victoria Embankment to Byward Street, is not expected to exceed 1 minute even during free flow conditions)."

Hence we can conclude that actual increase in journey times will probably range from zero in congested times to 60 secs at free-flowing times. I trust that this clarifies the issue.
Rod King, Cheshire 20's Plenty for Us

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We have used information provided in the City of London press release which says the new 20mph limits will "add only minutes to journey times". You can see the release here:
Nick Rawlings, editor, Road Safety News

Agree (14) | Disagree (0)

I'd like to know where the evidence is that 20mph limits reduce the severity of collisions because serious injury rates have increased in all the 20mph areas that I know of. They certainly went up in Portsmouth (the largest 20mph area in Britain) and here in Slough in Manor Park (North, South and central).

I think the 20mph road safety experiment is worthwhile trying, and may bring other benefits, but we must use simple scientific trials to determine the road safety effect. It seems that London are not going to use scientific trials thereby missing yet another fantastic opportunity to show road safety professionals and the public what effect 20mph actually has.

Huge amounts of our money is being spent on 20mph so shouldn't the tax-payers be able to expect that we provide the best evidence of what effect their investment actually had?
Dave Finney, Slough

Agree (16) | Disagree (9)

25 secs is the maximum extra across the widest 1.6m journey in City of London, not minutes as you incorrectly report.
Anna Semlyen

Agree (4) | Disagree (10)