The Automobile Association supports 40 km/hr on most roads in Auckland’s city centre, and rejects Auckland Transport’s proposed 30 km/hr speed limits, on the basis that 40 has been successful in Melbourne. In response to this, I thought I’d do some research into Melbourne’s speeds. Specifically, I wanted to know the reasons Melbourne lowered speed limits from 40 to 30 km/hr in a small part of town near the city centre last year. I found there are lessons for Auckland in Melbourne’s story. We could save ourselves money and time, with less social disruption, on our own path towards safe speeds.

The new limits are part of:

a 12-month trial led by Yarra Council, backed by a $250,000 grant from the Transport Accident Commission. The area is currently a 40km/h zone.

Yarra mayor Daniel Nguyen said he wanted to make it safer for pedestrians and cyclists on the area’s smaller roads, which are often used by motorists travelling between the outer suburbs and the city.

One hundred crashes occurred within the new speed zone between 2012 and 2017. More than 90 per cent of the crashes involved pedestrians, cyclists and motorcyclists.

“We’re looking at seeing if the trial will change driver behaviour and whether pedestrians and cyclists can reclaim the streets a little bit,” said Cr Nguyen…

Sam Luck, principal of Collingwood College’s primary school said the new speed would help protect more than 80 per cent of students who ride, walk or take public transport to school…

Monash University Accident Research Centre Associate Professor Jennie Oxley, who will monitor the 12-month trial with Yarra Council and VicRoads, said researchers would recommend that the speed zone be rolled out more widely — especially in areas with a large number of schools — if the Yarra trial was a success…

VicRoads’ Safe System Road Infrastructure Program director Bryan Sherritt said it was one of hundreds of road safety initiatives funded through the $1.4 billion Towards Zero action plan, “which aims to ensure no one is killed or seriously injured on Victorian roads.”

So this trial is:

  • led by the Council,
  • financially supported by the Transport Accident Commission,
  • part of VicRoads’ safety programme,
  • welcomed by the schools, and
  • informed by Monash University research, which says (references removed for easy reading, and my emphasis added):

At lower motor-vehicle speeds, the driver is afforded greater time to recognise hazards, a reduced distance travelled whilst reacting to the hazard and after braking, and a reduced likelihood of losing control of their vehicle. Other road users are afforded greater ability to judge the speed of an approaching motor-vehicle, and more opportunity to avoid the collision. Importantly, should a collision ensue, the impact forces exchanged between road users decreases, and so too the probability that these forces exceed those able to be tolerated by the road users without sustaining an injury. Vulnerable road users are particularly sensitive to this interaction, and it has been demonstrated that the probability of severe or fatal pedestrian injury increases exponentially with impact speed. An often cited view, is that to offer greater protection for pedestrians in particular (as less is known about cyclists), the prevailing road conditions must discourage motor-vehicle speeds in excess of 30 km/h. It should not be overlooked; however, that the critical impact speed may indeed be lower than 30 km/h.

Auckland can watch Melbourne and ask: Are they getting value-for-money by lowering speed limits from 50 to 40, and then to 30, and only in small sections of the city at a time? So many schools lie just outside the area – could the trial not have been extended to include them? And how many cities have to successfully ‘trial’ lowering the speed limits to 30 before it’s considered essential rather than experimental? Here’s a little history.

In 2012, Melbourne lowered the speed limit to 40 km/hr in a 2 sq km grid of the inner city. While this was progressive, it was also a compromise between what science said would make the area vastly safer (30), and the status quo (50). At the time, safety and health advocates called for 30 km/hr in the CBD. Victoria Walks gave a readable and well-referenced submission:

Traffic speeds that prioritise vehicular traffic tend to result in poor walking environments where streets are hostile and dangerous to pedestrians. This is a major barrier for walkability and consequently a significant impediment to increasing the number of people walking. For instance, VicHealth research found that 63 per cent of parents believe traffic volume and speed is a barrier to their children to walking to school…

The evidence linking lower speed limits to increased pedestrian safety is clear–30 km/h is the internationally recommended safe speed limit for areas where vulnerable road users are exposed to vehicular traffic (as defined by the biomechanical tolerance to crash impact forces) (WHO 2008).

But, in a strong parallel with what’s happening in Auckland, the RACV (the Victorian equivalent of the NZAA) lobbied to keep speeds high:

Brian Negus, the RACV’s public policy general manager, said a 40 km/h speed limit was only appropriate for some roads in the city grid that have high volumes of foot traffic, such as Bourke, Collins, Russell and Elizabeth streets.

‘‘But it’s not appropriate for roads that have more of an arterial function, like King Street, Spencer Street and La Trobe Street, because they have city access and city bypass functions,’’ Mr Negus said.

Looking at the council documents from 2012, The City of Yarra (a part of central Melbourne) planned to lower the speed limits to 40, and then progressively change them to 30 km/hr in the years 2012 to 2016:

Once all local streets reduced to 40kph, begin progressive program of applying for 30kph speed limits in residential areas.

It didn’t happen. Whatever political and practical difficulties they faced trying to do it piecemeal, more 40 km/hr speed limits were introduced around Melbourne, but the lower speed of 30 km/hr didn’t get introduced until the current trial. This is 2 years after they’d intended to have already rolled out a number of 30 areas.

Now, with this small trial, they are paving the way for safer streets where pedestrians can feel much safer:

Just a 1km/h decrease in a car’s speed could lead to a 3 per cent reduction in road crashes, according to the World Health Organisation.

The 30km/h trial will run for 12 months in Collingwood and Fitzroy.

The 30km/h trial will run for 12 months in Collingwood and Fitzroy.Source:Supplied

Despite the ample research, the RACV has continued with their resistance, arguing against this new 30 km/hr trial:

But the RACV’s mobility advocacy manager Dave Jones said the move was a waste of money, as average speeds on many of the streets were already close to 30km/h.

“We think the TAC’s funding would be better spent on making high speed country roads safer, or providing separated bicycle lanes and paths along busy arterial roads,” said Mr Jones.

The motoring body backs 40km/h zones on a “case by case basis”.

Brisbane is also trying for 30 km/hr. And Sydney will be watching the trial closely. They followed Melbourne in 2014, with the implementation of 40 km/hr in central city areas. And there, too, scientists advocated at the time for 30.

Even in this small trial area of Melbourne, they’re retaining 40 km/hr for some of the arterials, so additional changes can be expected in future.

Had Melbourne and Sydney been able to reduce their speed limits to 30 km/hr in one large area, not just to 40 km/hr in selected pockets, there would have been a number of wins:

  • people would be alive today who are not, and many serious injuries would not have occurred,
  • more people would be getting exercise in a healthier, more walkable environment,
  • the change in speed would have been more consistent and thus easier to adapt to, and
  • the city councils and public would have saved both time and money on multiple stages of consultation, entry treatments, trials, signage and documentation.

Auckland has been slow to respond to international success with 30 km/hr speed limits, but the benefits of coming late to any progressive move is being able to do it faster and with more certainty. Auckland has the benefit of evidence. Let’s speed this process up.

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  1. I personally think the lower the better, motorists in Auckland tend to drive +10km/h a lot of the time anyway and get away with it. So I don’t know what the AA is on about.

    1. Here’s their latest: They contradict themselves:

      “The AA supports efforts to bring down speeds on high-risk Auckland roads” …
      “However, on busy arterials like Hobson, Fanshawe and Nelson Streets, the AA is questioning whether speed limit reductions are workable.”

      Those listed streets ARE high-risk Auckland roads – I gave the map of high risk roads in the CBD in this post:

      I note they no longer reference Melbourne, as they had in the New Year’s Even opinion piece. Perhaps they’ve finally caught up with what Melbourne’s doing, too:

      “Cities like Melbourne and Sydney have introduced 40km/h limits in their CBDs and have seen substantial crash reductions. Closer to home, a 40km/h limit has worked well on Ponsonby Rd. So the AA will call for the new limit in the CBD to be 40km/h, not 30km/h.”

  2. The +10kph seems to be a uniquely and dangerous New Zealand thing. Semi officially sanctioned by our hands off, education is preferred , and seriously under resourced by deliberate Government budget descisions.

    1. Sorry missed and important word out in my post, and the edit function on this site.
      Should have read, and seriously under resourced ENFORCEMENT by deliberate Government budget descisions.

    2. Kind of seems dependent on the area too though, I recall driving through Whangarei a number of times and everyone was strictly 50 through 50. In the Auckland isthmus and city this generally seems to be followed too, but out West and North especially it feels almost criminal to be doing less than 5 over. Also 30km/h like Grafton bridge tend to just get treated like 50km/h by the majority of motorists (when its open to them).

    3. The UK used to be +10mph and one wouldn’t get stopped by the police, at least on the motorway. (And one might hope to get away with +15mph). Now, with enforcement cameras as close as 50m apart along the motorway gantries (along with variable speed limit signage), it appears to be +3mph. As in, everyone seems to set their cruise control to be the speed limit plus 3mph (thus to keep one’s distance and the flow, one does the same).

      1. NZ used to be +20 kph on the motorways. Then it was dropped to 10% tolerance, but now it seems to be a flat +10 kph. With +5 kph during the holidays.

    4. I think the 4km tolerance they set during the holiday periods makes more sense. People tend to stick to the actual speed limit (where the lines are on the speedo) but it still allows some tolerance to the odd accidental speeding.

        1. I just can’t understand that problem. Put speed cameras everywhere. They must be cheap by now. Tape some iPhones to power poles and I’ll write an app to do it!

        2. Low enforcement is ideological; it’s in some parts of Council too, and of course we’ve seen it shame NZTA. The government, AT and the Police need to hear it from the public: enforcement of all sorts of issues relating to traffic is required to provide access for our people, and return safety to our streets. It’s more cost-effective than other measures that get ignored anyway.

        3. I think you are right Heidi. If the police were more tech savey they could be busting lots of bad drivers. For example, is there a website where you can upload video of a bad driver? Why not? That alone would probably do better than the entire (almost non existent) police traffic enforcement. I could have personally uploaded 3 videos this week. Take that a step further, why not sell a camera device that will automatically upload an incident to police on a button click. I’m sure plenty if people would buy one. And plenty of people would follow the road rules.
          The only reasons for the police not attempting to adopt any road policing technology is either extreme stupidity or political.

        4. The police had some technology and contract issues. Both due likely to under investment by the previous government and lack of concern by the previous Minister.

          1. They had 32+ cameras, but could only monitor 8 at once.
          2. They didn’t even bother monitoring those.

          Recently they have fixed these systems and I think more cameras are being installed.

          Fingers crossed.

          PS: Some guy in Australia build a cheap app:

  3. We have had a campaign in Paekakariki for quite some time about reducing speed. It is surprising how much opposition one gets. One problem is it is clear in our situation we need some traffic calming devices given how wide and straight our roads are. Various people object to the available tools, especially speed humps. One put forward is they damage older cars. But the more we see speed restrictions being brought in in other places – and the sky doesn’t fall in – the stronger our arguments become locally.

    1. I was talking to someone now involved with accompanying children to school on bikes. He said he thought he’d been a safe driver before, but that this experience has changed everything about how he drives. I think that’s probably a way forward – trying to pre-empt resistance within each community by asking for volunteers to help accompany the small kids. It would build up a group of safety advocates who can tell their own stories. When there’s opposition, perhaps an invitation can be made to the people opposing, to come and help with the kids. If they refuse, plenty in the community would dismiss their views.

      1. When I drive now. I try to either stick strictly to the speed limit, or on residential streets drive slower.

        Personal action is a start.

        1. I must admit, even though I want the speed limit to be slower, when I drive I do tend to drive at speed limit + 10. Basically I don’t really see the point in me driving slower if everyone isn’t doing it.

        2. Try driving 30 kph around schools and your (or my) local streets. Slow down around cyclists. It’s not hard. Do it for a day, week. See how it feels. If it makes a difference to your travel times.

        3. I do slow down for schools and cyclists. Being a cyclist does give you a much better understanding of how fast cars seem even though when you are in the car it feels slow.

        4. I thought this was interesting, from the Brake website:

          “Dutch research has found drivers with one speeding violation annually are twice as likely to crash as those with none, and this increases further for drivers who commit repeated speed violations [5].”

  4. Lower speeds are reinforced by narrower roads which opens up more space for other transport modes and street activities. If the rules are enforced you can lower speeds even in roads which shout highway but why not narrow lanes remove the odd one and widen the footpath?

    1. Well they do need some wide roads to move oversize vehicles and stuff. So those roads need to be enforced by speed cameras and police. Whereas other roads can be enforced by narrowing the roadway, tactical urbanism and speed bumps/tables. Yes you are right another great advantage of narrowing the roadway is you can get wider footpaths, these could generally be shared paths and encourage modal change.

      1. It is okay to narrow road (in NZ we can narrow the lane to 2.5m) and still have access for oversize vehicle, we can do this by having obstacle free zone each side of the road.
        If you compare 2009 snap shot with 2018 image you can see many of the obstacles removed.
        This is good example of the Dutch process in making there streets more forgiving.

    2. That certainly needs to happen, but the reasons this can’t be done immediately are:
      – Nothing happens quickly. The behemoth is a slow beast. In the meantime, people die, lives are torn apart, and people are not getting enough physical activity. Changing the speed limits has an immediate effect – and with enforcement, it can be a big effect.
      – Aucklanders are driving arrogantly – too fast past parked cars where children could step out at any time, running red lights, parking all over footpaths and cycleways, too close to cyclists, not stopping at crossings, leaving people stranded in the middle of the road. Drivers are not driving appropriately for each built environment, so there’s no point trying to change the built environment to suit the drivers. A complete shift in understanding is required. New speed limits, new enforcement is part of this.
      – The cost of changing every street is beyond us. We need to change the driving culture first, and change the built environment in those places where that’s not enough.

      1. The cost of changing speed limits and enforcing them on every street is minimal, not that it is needed on every street. It is the cost of building traffic calming engineering features that is huge and considering, many would be redundant anyway at appropriate lower posted speeds I cannot understand why they have been adopted as primary speed reduction measures to date.
        Speed limit signs though without enforcement though, just bring an element of respectability into non compliance with the law. The AA’s statement against lowering speeds because it will cause compliance issues is as stùpid as saying we should not ban indoor smoking as it will cause compliance issues. They did ban it, and the required enforcement quickly dropped to minimal levels.
        My reservations with the planned speed reduction boundaries is that they did not go far enough. Freemans Bay is a defined area between the College Hill, Ponsonby Road, and K Road Ridges yet the speed limit is dropped in only half the suburb. Absurdly the half in which schools are located retains 50kph limits. This will also double the number of signs required.

      2. Traffic-calming IS a type of enforcement: street self-enforcment. And it is permanent, and it is something we very much need on all access streets. So that some future government doesn’t ruin everything within a few months.

        1. And it is agnotisic. It will save people’s lives either from malice, a sneeze at the steering wheel, etc.

          I don’t see the purpose of restricting their construction because it would ‘serve’ a bad driving culture. It will change behaviour as it physically breaks the cycle and has repetition to it, and it will safe people from more than just bad behaviour.

          Building the environment to serve such a driving culture would actually be more like making every driveway aa highway 😛 Now that will reinforce the cycle!

  5. I hope we do not see AT fold and put in 40kph instead of the 30kph. Seems to be a history of doing so when pressured, or when they get a little bit of negative feedback from a minority. Hopefully the clear accident/death reduction aim sees them hold their nerve on this.

    I do wonder if we could introduce 30kph around all schools.

    The introduction of the subtle ‘your current speed’ signs around parts of Auckland has been pretty effective at making people think and alter their behaviour.

    1. It would be really nice if the Government would lend a bit more open support to Act’s adoption of a 30kph standard. Step up Phil please, now would be a good time given that a lot of NZTA’s problems are the result of the years of the previous government’s ineffective political oversight.
      Not a regime you want to continue Phil.

      1. It would be really nice if Act supported the proposed 30kph speed limit as well but I am grateful of just AT’s proposal.

  6. Note, Melbourne’s CBD limit will remain at 40kph – the proposed 30 kph is a separate area north of the CBD. This is not stated in this article above. So maybe GA should be campaigning for 40 not 30, with 30 around schools.
    While reducing the speed limit in parts the CBD and elsewhere makes sense, a blanket reduction to 30 kph does not.
    I am yet to see a proper breakdown of the real causes of the DSI in the central city. i.e. how many were actually due to people travelling more than 30kph. And where are they happening? How many involved cars? How many were drunk? How many were suicides? How many were cyclists not involving a vehicle?
    Yes, I understand that the risk of death at 30 kph is much less than 50 kph and people don’t deserve to die for being stupid.
    I fully agree that better crossings need to be added to the likes of Hobson and Nelson St. Without them , all the 30 kph limit will do is make more people just randomly cross than do now as they will think it is safer.
    We also need to educate people around looking before crossing, and look up from phones as you walk etc.

    Finally I suggest people try and drive at 30 kph and see how slow it actually is. To give you an idea average cyclists will be passing you (so will also will be slowed down with new bylaw).

    1. “the proposed 30 kph is a separate area north of the CBD. This is not stated in this article above.”

      I wrote this in the first paragraph, Stu: “in a small part of town near the city centre”. This area is 1.1 km from the edge of what Google consider the “city centre”. Is that not ok to call ‘near’?

      AT’s done the work on what the Auckland city centre needs. It’s 30 as a maximum. They’ve got plenty of evidence online. If you know something they haven’t addressed there, please provide a link.

      If it feels too slow to drive at 30 km/hr in the city centre, adjust what you think is appropriate.

    2. “To give you an idea average cyclists will be passing you”

      Currently, most cyclists on our streets are confident cyclists, more likely to travel fast. The speed of those who would cycle in a safe speed environment will be much lower. Our kids would start cycling again. Rates of women cycling would rise. The “interested but concerned” demographic would start cycling.

      Some cities have lowered speeds for exactly this reason: the modeshift, healthy lifestyle and opportunities it offers for people.

      AT are concentrating on safety in this first consultation but they will hopefully shift gear soon and talk about the many more lives that will be saved through the healthy streets aspect.

    3. Hobson Street would definitely be on the list. There is an amount of people living on that street comparable to an entire suburb.

      And yes people will randomly cross. That’s the point. You would impose a delay of 5 minutes (that’s a detour to a traffic light, and often a long wait) on thousands of people who just want to get to the other side of the street, so a couple of drivers can drive to the spaghetti junction a few seconds faster (note that Hobson Street is either a big queue during peak hour, or empty).

    4. Stu, I would be happy with a universal 40kph limit, with restrictions to 30kph around at-risk areas like schools, hospitals, town centres and parks.

      40kph is fast enough on city roads, not much slower than average speeds with moderate traffic, and I think it only seems slow because we have become conditioned to travelling at 50kph and faster.

  7. For the doubting Thomas’s amongst you go to the West Coast. Greymouth has reduced it’s CBD area to 30kph and it’s a joy to walk around their town. Hokitika, just down the road has not and I felt at risk wandering around there so stayed in my car with my wallet in my pocket. Greymouth was the recipient of my tourist dollars. Hokitika is now going through the same wretched hand wringing exercise that Auckland is about to engage in. This is not an irreversible exercise. It’s not like we’re building another harbour crossing. If the sky falls in and AKL’s GDP collapses as a result of a change to 30kph I’m sure even Heidi would agree to give 40kph a go. AT & politicians grow some gonads and get on with it.

  8. As a Kiwi on a very extended OE in the UK, I got used to speed cameras and as my work depended on driving, I had to be very careful.
    At one time I was on 9 points out of 12 to achieve before being neutralised, drove like a Nun I did.
    NZ needs more cameras but like the UK clearly marked even though all regulars knew where every camera was on frequent routes, it worked.
    Red Light cameras work effectively and still make me stop here or get ready to stop with high tension even though a camera isn’t present.
    Average speed cameras are in my opinion the most effective and fair and allow for minor incursions into danger with the option to recover by dropping speed for a while!
    Not sure if I can link an article in UK Daily Mail today re Speed Cameras and history and use of.

  9. Ordinarily, I’d be totally in favour of measures that improve safety. In this instance, however, I don’t think the argument has been won. The data provided thus far by AT only draws an association between vehicular speed and injury/death rates (and actually, their infographic doesn’t even do that – the only conclusion you can draw is a trend towards more injuries and deaths on roads). The far more cogent question is how or why vehicular speed is even a factor, eg, vehicular speed might increase risk of death of any persons involved in an event, but it doesn’t seem established that vehicular speed CAUSES those events in the first place. I don’t recollect hearing about screeds of motorists driving down footpaths, cycleways, footbridges etc mowing down innocent pedestrians, cyclists and lemmings. Therefore, these events must be occuring on shared spaces where cars and pedestrians may potentially meet, otherwise known as a street (okay statement of the obvious I know but sometimes it helps develop an argument). I focus on the word SHARED. Responsibility for events/accidents can therefore be attributed to either or any party involved. At best, It would be a fallacy or inefficient at best to automatically ascribe the majority of responsibility for such incidents to motorists, or, at worst, an injustice/iniquity. Living, playing and workin in the city centre, and driving, I can honestly state that idiot drivers frustrate me as often as stupid pedestrians who seem to think their flesh WILL win a contest of survival with steel. The most common culprits on 2 legs seem to typically young “Superman” 20 somethings – yes, i know i’m using stereotypes which is a weak argument, but in the absence of any data this is all I”ve got. WHich brings me back to my point – WHY are there accidents in the first place – we just don’t have the data. All we have is a) drivers drive at 50ish kph b) ppl getting injured by cars, ergo c) must be cars fault. As a medical person, this is analogous to me saying to a patient “Bob, you’ve got knee pain when you walk the dog. Get rid of the dog, mate, that’ll make the pain go away….what? WHY are you getting pain? Firstly, Who cares – I’ve just told you how to make the pain go away. Secondly and obviously, it’s the dog causing your pain….”. Establish the data and win the arguemtn. Or if the data ends up showing that the number of accidents has nothing to do with motoring speed, then make other changes that are more likely to address t he root cause of the issue.

    On another point – from a practical perspective, is this measure really justified? AT has been quoted as saying vehicular speed at peak times (presumably when the probability of accidents increases as more human flesh presses up against metal chassis – yes an assumption, but again, my point about no data) is already below 30kph. How many additional accidents will be prevented by having lower vehicular speeds outside peak hours (when the effect of this intervention, you would assume, would be diluted by space)? Are we lowering the threshold for speeding infringements to prevent 2x broken ankles? (If I told you we’d have to prescribe a pill to 100, 000 ppl to prevent 1 heart attack, but cause 20 strokes – would you think it was worth it for society as a whole?) – we don’t know, do we?

    Establish a reasonable arugment, and I’m willing to trade the extra time it takes me to cross the city to the motorway – but I’m not convinced by a graph merely showing rising deaths on AT’s roads and not much more.

    1. I’m hoping the biggest impact from the speed change will not be the speed. It will be the increased awareness and hopefully improved driving as people actually pay attention to the environment. Bringing the speed down helps drivers become more aware of their surroundings instead of just charging ahead as fast as they can go, ergo less accidents.

      Maybe then, once we have a better driving culture we might be able to re-consider the speeds on certain roads.

      1. Totally agree with your comment about driving culture, just not sure that a reduction in the speed limit is the mechanism to catalyse that. If there is sound scientific reasoning to suggest it would, I’d actually swing in favour of reducing the speed limit. But again – we dont know, do we.

        1. You seem open to learning about the research, which is great, Trip. Just not sure which of the many links I gave you’ve read, and which you haven’t. There is solid evidence that:
          – faster speeds lead to more crashes;
          – faster speeds vastly increase the level of injury and the likelihood of death;
          – safer speeds (ie slower) allow more peripheral vision, eye contact, social connection;
          – safer speeds create mode shift, because people find it safe enough to journey on foot or bike where they wouldn’t have before (or wouldn’t have allowed their children to do so)
          – safer speeds in a through-traffic area can increase the volume of traffic (through more efficient traffic flow)
          – safer speeds in a residential area can decrease the volume of traffic in the area (due to mode shift and route shifting off the ratruns to the faster arterials)

          Links I gave above that might be useful are:
          – the Monash University research, and all the research they link
          – the Victoria Walks submission, and all the research they link

          Some other Inspiring websites:

          This one’s an oldie but a goodie:

          There’s information on why 30 is appropriate for urban streets in the UN, the OECD, the EU, the ITF. Happy reading!

    2. “The far more cogent question is how or why vehicular speed is even a factor, eg, vehicular speed might increase risk of death of any persons involved in an event, but it doesn’t seem established that vehicular speed CAUSES those events in the first place. ”

      Vehicular speed is a factor in every single injury, we are trying to prevent (or lessen) injuries, not crashes.

  10. Trip
    What does it matter who causes the accident? Over your lifetime you will have at some stage been too young to be responsible, you will most certainly had unplanned falls and stumbles, missed seeing something, or hesring something important. I bet you have already had errors of judgement. Hopefully you will live long enough that these impediments are likely to be part of your lot. Dropping speeds from 50kph to 30kph will means that these failings about these roads are much less likely to kill you or your children or aged relatives. All to save just a very few seconds to drive to the other end of the street. What useful thing are you going to do with those seconds. You may well lose them in the extra time required to get across the first road you then have to cross on foot.

    1. Thanks don, you flatter me with your implication of my youthfulness. If only! I will have to disagree with you, though I admire the generosity of your forgiving nature. I think it very much matters either a) who causes the accident (if Bob decides to jaywalk across K Rd on a dark night despite there being a controlled pedestrian’s crossing approx every 50 with no regard for traffic, then how is it the responsibility of Bill who is driving home along K Rd with his trunk full of yummy groceries if the two should meet? Should the jaywalking pedestrian also not bear some of the inconvenience of reducing crash risk?) or b) what caused the accident (there may be systemic issues that promotes unwanted contact between humans and vehicles – in many places, pedestrian traffic is separate from crossing roads through elevated footbridges, tunnels etc, as an example). And to your point, i’ve seen AT commenting that operational road speeds are already well below 30kph on the roads within the area of interest – it’s almost like they’re trying to say “oh we won’t lose anything really” but I view it the opposite – what’s the point if they’re effectively already below 30kph, and the rate of death/injuries are still rising? Doens’t that boslter the argument that other measures should be studied and undertaken?

      1. It would be incredibly harrowing to be involved in a fatal or serious injury accident even when completely clear of any fault. Even the time taken up with inquiries etc whould amount to years worth of any time saving of that extra speed.If you travel at 30kph rather then 50kph you will have had both a better chance of taking effective evassive action, and any if collision still occurs, the vastly reduced kinetic energy involved whould much reduce the severity of the injuries. Once average speeds are decreased the outlier speeds also fall, it is those travelling at these outlier speeds who are most likely to be involved in accidents, and the consequences of those accidents are the most severe.

      2. Trip, I don’t know how much you walk around Auckland. We have a serious problem of unsafe pedestrian infrastructure. You might like to read the Road Safety Business Improvement Review. The reasons pedestrians are being hit are not something that can be fixed with simplistic solutions that place blame on vulnerable road users who have been ignored in measurement, design, funding, priority for decades.

        A city that caters to its youngest and its oldest is a city that thrives.

  11. Interesting stuff, Heidi. As it happens, next week I will be presenting at the NZ Transportation Group Conference on “The mechanics and politics of changing a speed limit”, looking into why this seems to be quite hard to do in NZ. The paper examines some of the arguments stated for and against speed limit changes (particularly lowering speeds) and how we might make some progress in NZ. You’re welcome to have a read of it already –

  12. “Silly me”

    Very perceptive.

    The kinetic energy that is dissipated in a crash is proportional to the square of the speed and thus a vehicle travelling at 30 km/h has 36% of the kinetic energy it has at 50 km/h. That’s the relevant physics.

    How about some injury and death data as a function of speed?
    (Refer death and injury risk percentages)

    To state that “vehicular speed might increase risk of death” is disingenuous. There’s no *might* about it. It does.

  13. If this is to be emulated anywhere in NZ the limit will have to be 20kph. Because NZ has this strange mainstream driving culture where people try to keep their speed roughly 10kmh over the limit.

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