20 MPH zones don't work!

The Green end of the Bristol blogosphere’s been getting rather excited about 20mph zones for the majority of residential streets in Bristol. Not everyone’s convinced …

A guest post by 2nd Anonymous

20 MPH zones haven’t made any difference for the past 10 years in my street in east Bristol. Why would I lie ? I’m not making that up.

I’d say that 10 years is long enough for a scientific study, but apparently, some of you think you know better. Wussy comments like “20 mph is backed by facts” are hardly going to convince me are they now, when I’ve conducted a 10 year (that’s ten years, not 10 minutes on Google) study, or rather, had a 10 year experiment conducted right under my nose.

So, I’ve been hallucinating the traffic travelling at 35-55 mph have I? The video evidence which I took some 5 years ago, when I still thought that was a worthwhile use of time has been speeded up has it? Don’t make me go scrummaging around to find the tape and put it on YouTube. Just take my word for it, pretty please with chocolate balls on top.

Maybe in the leafy suburbs of Southville, everyone’s uber nice and co-operative and law abiding and respectful and maybe some ridiculously flawed study at the institute of pulling-the-wool-over-our-eyes in some make believe city came to the erroneous conclusion that 20 mph zones work (on the day that they happened to be looking that way and not picking crumbs from their beards) but it hasn’t worked in my street. Can you get that?

Do you want me to wheel my daughter on to tell you how long we have to wait by the side of the road in the morning rush hour to cross? Of how we’ve had to dash across sometimes, nearly getting run over, often beeped at by motorists, the kindest of whom couldn’t slow down to even 25 mph if they wanted to, because some git is doing 40 mph up their rear?

Can I stop now? Or is some clever canute going to tell me I’m still wrong and that 20 mph zones work?

Well, I sincerely hope yours do, but, as I think I might have established by now IT DOESN’T WORK IN MY STREET.

This entry was posted in Blogging, Bristol, Bristol East, Cycling Demonstration City, Environment, Green Party, Local government, Politics, Southville and tagged , . Bookmark the permalink.

28 Responses to 20 MPH zones don't work!

  1. We at Bristol Traffic celebrate your optimism!

    Laws that are not enforced do not exist. In traffic, that means that rule 17o of the highway code -pedestrians already crossing a road have right of way over turning cars- doesn’t exist anywhere in Britain.

    20 mph zones in Bristol will only exist if enforced. Those roads that were selected are those that have an average speed of 24 mph, so half the cars are already within the effectively enforced speed.

    The main roads have been left out -the ones that are hardest to cross and most dangerous to cycle on- leaving their speeds up to 40 mph. This is why the cycling campaigners “subversives” want 20 mph across whole areas. No ambiguity, less signage, slower cars turning. Some of them also think that rule 170 rights-of-way-at-junctions should be enforced across the city, along with rules about where you are allowed to park.

  2. Ella says:

    I walk faster than 20mph.

  3. bikeman says:

    slow down, you move too fast, you’ve got to make the morning last

  4. Chris Hutt says:

    This is a very interesting debate.

    Firstly I would say that we really should listen to the comments of people who have experience of living in a street with a so-called 20 mph limit. Their first-hand evidence should not be dismissed because it doesn’t conform to the pro 20 mph propaganda.

    I’m quite convinced that reducing traffic speeds makes our streets feel safer, so encouraging people to walk or cycle. That’s backed up by lots of evidence as well as common sense. And lower speeds mean reduced pollution, noise and stress. So for me the question is how to reduce speeds rather than whether to do so.

    Declaring 20 mph zones appears to reduce the average speed of traffic, based on past experience, but that does not mean that all the traffic slows down. The reported speed reduction is based on the average speed (the ‘mean’) but an average speed of 24 mph (which is the target) might mean say 60% of the vehicles doing 20 mph and 40% doing 30 mph (so 6 x 20 + 4 x 30 = 240, which divided by 10 = 24).

    In practice an average speed of 24 mph might include a few % doing 36 mph or more. Yet it is that small % who determine how unsafe the street is perceived to be, not the majority doing around 24 mph. So I would say that more emphasis should be given to dealing with the highest speeds and less to achieving a low average speed. That indicates the importance of enforcement, without which a very small minority will undermine the benefits deriving from the larger group who comply with the speed limit.

  5. steve meek says:

    can you tell us what street? I can think of several ‘advisory’ 20mph streets in east bristol but they are quite pointless. Lower Ashley Road, Easton is my least favourite….runs past millpond school and a rat run for the M32.
    Or is yours a mandatory one, with red bordered signs, like the subtle, easily missed one at church road, redfield?
    IMHO the best way to enforce low speeds is not through the police but to change road design in those areas.

  6. the jolly blogger says:

    Police don’t touch 20mph zones with a 20ft barge pole complaining they’re difficult to enforce. Therefore the council needs to make them self-enforcing with speed bumps/cushions and build-outs which gives the traffic going in one direction priority. If a 20mph zone isn’t effective it’s generally down to the speed calming measures not being up to scratch. 20mph zones are also used by councils to make rat-runs less attractive to motorists.

  7. Chris Hutt says:

    JB, those are the attitudes that need to change to make 20 mph zones work. Speed enforcement is in fact very easy and can be largely automated, so there isn’t really any excuse for the Police not doing it. But they themselves have ambivalent attitudes.

    Traffic calming measures are expensive to install and maintain and have adverse side effects like noise generation. We need to move beyond treating motorists as dysfunctional children who have to be physically restrained from bad behaviour. For the most part they’re responsible adults perfectly capable of exercising self-restraint if they can see the point in it.

  8. Tony D says:

    Unfortunately, responsible adults are also perfectly capable of exercising high levels of selfish behaviour if they can see a gain in it, however ephemeral the gain might be, and particularly if there is a very limited chance of punishment for any transgression.

    I am not sure if the original comment by “2nd anon” is a valid argument against the use of 20mph zones (unless he is saying that a 20mph zone actually encourages motorists to go faster?) so much as an argument that the zones initiated so far (or, rather, his particular one) are obviously not up to the job.

    I hate to spoil this thread by introducing facts but there is plenty of evidence from residents of existing zones elsewhere in the country where 20mph zones are working in their areas – so perhaps is just us “local yokels” who aren’t doing it right (unless the residents of places like Hull have been “hallucinating” for the 15 years or so and are making it up).

  9. Traffic Cop says:

    I’m looking forward to this 20mph limit. It’s going to be fun nicking some of these bloody cyclists for speeding!

  10. Des Bowring says:

    Anecdotal evidence is not necessarily a reason for not doing something so despite the original piece I say give it a go.

  11. Glenn Vowles says:

    20mph zones certainly can work and in maany places have been shown to work. You have to get the designs right. You need a proper set of plans for doing it. A 20mph strategy (which is essential)is unlikely to be as successful if its not very widespread. Now, can we trust this council to these things and more to make Bristol’s streets safer, quieter and healthier?? Doh!!!

  12. Rosso Verde says:


    Here’s some stuff from Leicester Greens who have implemented it.

  13. Traffic Cop says:

    20 mph zones are only as good as the enforcement. In Bristol, enforcement is usually feeble. As I have already pointed out though, I will be vigorous in the enforcement of these new regulations against speeding cyclists; especially if those speeding cyclists happen to be green trots!

  14. Charlie Bolton says:

    Chris Hutt hits the nail on the head. The zones should lead to a small reduction (a few mph) in speeds on average – from the law abiding. The idiots still speed.

  15. Rosso Verde says:

    Traffic Cop, oooh, I’d better watch out 🙂
    Although I’m pretty slow on my bike (too fat)
    Agree with Chris Hutt and Charlie’s statements, 20 mph zones are a good thing, but need to be more than a “box” ticking excercise – there needs to be genuine backing for Traffic Cop and his mates in stopping naughty speeding Trots, Islamofascists and even Liberal Democrats.

  16. Chris Hutt says:

    I’m glad we agree on that Charlie. So it follows, does it not, that effective enforcement needs to part of the plan, targeted at the minority of worst offenders rather than the majority who may treat the limit with some discretion.

  17. onthelevelblog says:

    The important thing is getting the law in place- the support for enforcement will come later. And yes residential roads need traffic calming as well, but drivers need to realise that the law is on the side of children playing, pedestrians, and cyclists, the most vulnerable road users. At the moment its open season (or at least that is the message a default 30mph limit sends out).

    Implementing 20mph for residential Bristol will arm the police with one more law they can throw at dangerous drivers, and yes these young male boy racers are responsible for more than their fair share of deaths and injuries and they do need to be the target of enforcement.

    The time is right- the question is, does the Council have the cojones to do the right thing? If they don’t take this easy, inexpensive, relatively uncontroversial policy measure to reduce the slaughter on our roads, then the Bristol City Council will have blood on their hands.

    Pedestrian hit under 30mph: 45% fatality risk
    Pedestrian hit under 20mph: 5% fatality risk

    More info at: http://20splentyforus.org.uk/

  18. old misery guts says:

    What happened to the support for a Mondermann approach to traffic management? Remove all the signs, all the traffic slowing devices, all the nanny state and see what happens. (It worked in Holland apparently, although of course the Dutch are much more grown up and sensible than us, allegedly)

  19. Bluebaldee says:

    The best way of guaranteeing 20mph zones is to allow congestionto continue to grow until no-one can ever drive faster that 20.


  20. Dona Qixota says:

    This just seems as if it’s all about those in charge paying lipservice and mouthing green and sustainable to make themselves look like they’re doing something (when they’re not).

    These so-called leaders live in a fantasy land where laws are all about “sending signals”. Like Laurie Anderson said it’s all about words, words, words. They think words are reality. They think that if they pass more and more laws that people will magically “improve” and “be good.” New Labour have passed well over 3,000 new laws since they got in, hardly any of which are enforced, or if they are, it’s often on an ad hoc and therefore completely unfair and discriminatory basis.

    Having so many crap laws and then not enforcing them is really bringing the law into disrepute, which threatens to undermine democracy dangerously. If people are to start taking the law seriously again we need to get rid of all the rubbish laws. We could start with the drugs laws. The War on Drugs can never work, causes social and environmental problems, only benefit organised crime and make cosy moralists feel pious.

    Until there’s the perception that we’ve got a reasonable, understandable, and fairly enforced set of laws, hardly anyone’s going to take a bit of notice of things like 20mph limits, imo.

  21. 2nd Anon says:

    Totally agree with Dona Qixota, so does my 8 year old kid :

    “Having so many crap laws and then not enforcing them is really bringing the law into disrepute, which threatens to undermine democracy dangerously.”

    This was the point of my original rant.

    It’s galling to have lived in a 20 mph ‘Home Safety Zone’ for 10 years in east Bristol and to witness the daily flouting of this speed limit, as we wait by the side of the road for a gap in which to dash across.

    Chris Hutt can try to get clever with his statistical means and averages and mathematics, but the reality is, unless you’re my 86 year old dad, motorists drive at the speed of others around them. It’s the herd mentality.

    Sure, my street’s a rush hour ‘rat run’, not a road-to-nowhere side street, so it’s going to have a greater density of traffic, driving at a higher speed and therefore requires more effort to enforce.

    But nobody has.

    How do you explain to an 8 year old kid why all the cars are doing 35 mph+ when they should be doing 20 and that when the sign says ‘Home Safety Zone’, it’s not ?

    Hold my hand tightly now, we’ll try to dash across after that red one………..

  22. Traffic Cop says:

    One of our old school coppers has just suggested that all traffic laws be abolished, but, that if a motorist causes an RTA, or knocks over a pedestrian, they should be hanged!

    He’s convinced it’d work. It would certainly simplify my job, I’d be able to spend more of my shift eating sausage rolls and sleeping.

  23. Dave says:

    An ardent petrolhead speaks:

    I agree with 20mph limits in the right places. For example – most residential streets. I have just moved to a street which is a 20mph zone which I will stick to; firstly out of respect to my neighbours and secondly because the council has installed massive speedbumps which my low-bumpered car doesn’t really like – they really do work. I don’t have a problem doing no more than 20mph along it, safe in the knowledge that when I leave the street I can drive up to 30.

    Most traffic I have seen drive along the road doesn’t get much above 20 – especially the boy racers, because their splitters are so low they have to slow down to a crawl to get over the speed bumps.

    The speed bumps work as enforcement – the only time they don’t is if you have a vehicle with a wide track (e.g. a transit van) that can avoid them.

    That said I don’t agree with all proposals for 20mph limits – for example, Coronation Road?!?! This is a major road with high volumes of traffic in rush hour. A 20mph limit along a main road with good visibility and more importantly, traffic-controlled crossing points, is absolutely ridiculous and could just cause more congestion with no benefit whatsoever to anyone.

    As I said however, I wouldn’t have a problem with a 20mph limit on most residential streets, but it simply isn’t enforceable without speed bumps. And can you imagine the expense to kit every street out with them?

    Especially as I would prefer the speedbumps they have trialled abroad, where it stays completely flat if you’re going slow enough and only raises if you’re going over the limit – a brilliant idea.

  24. Chris Hutt says:

    Dave, why won’t you (and/or other ‘ardent petrolheads’) respect a 20 mph limit without there being speed humps to enforce it? Are you willing to pay for the installation of the speed humps? Would you respect a 20 mph limit if it was enforced with cameras, say?

    I’m always amused when motorists who say without hesitation that cyclists should obey road traffic laws become so ambivalent when they are expected to obey speed limits and parking regulations (and vice versa in some cases).

    On congestion I think you will find that the capacity of an arterial road like Coronation Road is maximised at around 20 mph rather than 30 mph since stopping distances (and therefore the necessary gaps between vehicles) are reduced and conflicting movements (such as right turns off the road) are easier to carry out with reduced delay to through traffic.

  25. Jimmer says:

    20mph zones can’t be enforced?

    Think again:

    No need for speed bumps, no escape for speeders.

  26. 2nd anon says:

    Yes, 20mph zones can be enforced if you’ve got the cash to spare.

    But the ones here aren’t because there isn’t.

    Making it all rather frustrating, pointless and still dangerous.

    Seems the best solution is more snow. That certainly slowed the buggers down this week.

  27. Dona Qixota says:

    Re: cameras … And then wonder why we have a surveillance society … ! There’s no easy answers to the over-complex modern social mess is there.

  28. Adam says:

    Roseberry Road, Bristol. It’s been a 20mph road in a 20mph zone for a long time now. Doesn’t make any difference. On any given day you’ll be able to find people doing 40mph or more down it. Most people at least 25 to 30mph. A few might do 20mph but probably as they live there or are looking for someones house.

    It has a reputation as being a quick shortcut that you can drive faster down. I’ve been told this on a number of occaisions by drivers / contractors visiting my house.

    Even the surrounding are with chicanes and speed bumps don’t stop people speeding in between them to gain priority over oncoming traffic through intimidation.

    And Church road is a major road that has had a 20mph section for many years. Go and have a look at how effective that is. If I drive 20mph down it I get people sitting on my bumper and beeping. Cycling up it is even worse with all the cars parked in the ( showcase bus route ) bus lane.

    All a bit of a joke unless it’s enforced and more speed bumps isn’t the answer (they’re terrible for the emergency services). Getting people to actually care and be considerate of others is the answer. Not sure how you do that though without punishing people in to it through use of fines and enforcement sadly.

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