Speed Limit: Where’s the Proof?


Over the Christmas period, once again the police are imposing a speed limit reduction for motorists.

Between Christmas Eve and January 5, the tolerance for exceeding the speed limit will be reduced to 5 km/h.

Central District’s acting police road policing manager, Senior Sergeant Kris Burbery, said in a statement: ”Please remember the speed limit is that a limit, it is not a target and staff will be rigorously enforcing that tolerance.”

Has there been any proof this strategy has worked? I seem to recall that the last long weekend this was tried, there was a high toll.
If there isn’t clear evidence, it can be cynically seen as just another revenue earner.




  1. Draco T Bastard says:

    Two things:
    1.) The 10km/h leeway was because radar/laser speed detectors were only accurate to within 7km/h ATT. It’s entirely possible that they are more accurate now but if so then the tolerance needs to be adjusted fulltime.

    2.) The speed limit should be dropped back down to 80km/h anyway. It’s safer and uses far less fuel cutting greenhouse emissions.

  2. Brad Heap says:

    An 80kmh is not safer than 100kmh. In fact a few months back they had Mark Skaife on TV arguing that there should be no speed limit on double carriage ways.

    Imposing arbitrary speed limits actually increases the chances of crashes because drivers spend more time focused on sitting at a fixed speed than driving to the conditions.

  3. Decanker says:

    “Imposing arbitrary speed limits actually increases the chances of crashes”

    Ah yes, of course, there’d be far fewer fatalities if people could just ignore their speedo and drive as fast as they deemed possible.

  4. damian says:


    That is nonsense and proven not to be the case.

    While Mark Skaife can drive a car around a race track quickly he is by no means qualified to make such a statement.

    We need speed limits, purely to increase the flow of traffic and prevent deaths when accidents do happen.

  5. Tomas says:

    sorry but for a progressive transport website to publish kind of comment is really disappointing.

    firstly it infers that speeding is okay. which it isn’t - whether we all do it or not is different - we should all be aware that speeding is dangerous a 10% increase in speed (say 110Km/h) can mean 21% more energy some or all of which can be released in an accident, usually resulting in more serious crashes. What might have been a near miss or minor injury can be become serious or even fatal. Even if you are in perfect control of your vehicle - which is unlikely as increasing your speed greatly affects your ability to react with and control your vehicle - you cannot guarantee that other drivers will also be. Summary - slower speeds mean less and less serious crashes.

    Secondly it villainies’ police officers who are charged with trying - what a uphill battle this must be - to stop New Zealanders killing themselves on the road.

    thirdly this has been tried for the last two holiday weekends, the first was a major success with almost no (I can’t recall if it was actually zero) road deaths. Whereas the second time - last time - it was a huge weekend. , but I think mostly they were alcohol related so maybe the speeders weren’t out either. Any in case 2 trials should not give us enough proof to scrape or roll out this policy, more trials should be done.

    I for one hope they are successful.

  6. Nathan says:

    When Britain introduced motorways back in the 1950s they were initially “unrestricted” i.e. there was no speed limit at all. However, due to the number of serious accidents a 70 mph speed limit was introduced in about 1965 and remains to this day.

    There are also other reasons for speed limits besides accident rates, such as to reduce noise/vibrations and emissions from vehicles.

  7. James B says:

    Tomas asking for proof that something is working is disappointing? If this policy isn’t working then why do it. The police like every organisation have limited resources and if ticketing drivers for minor infractions starts to get in the way of policing more serious incidents then surely we should question why they are doing it. I for one would like to see a blitz on red light running. I have had zero problems with speeding motorists, but have almost been hit on numerous occasions by red light runners.

  8. AKT says:

    It was a question for debate not a statement.
    This blog fully supports any positive move to reduce the road toll and make driving safer for all

  9. Mike says:

    Recently been driving in England and the US on similar roads yet they have a speed limit of 112 and 120 km/hr ( converted to km/hr) .In those countries and many others I’m deemed safe to drive at those speeds yet here I would be classified as a speedster.

  10. damian says:


    After living in the Uk for 8 years, I can say and I am sure you’ll agree that their motorways are far safer than ours.

    Recently I was traveling up the M6 sitting on 85mph, so 15 over the limit when a cop came up beside me and told me to slow down using hand gestures.

    The only the reason I can think they did not pull me over, apart from not wanting to do the paper work is that the speed I was travelling at was deemed safe at the time, but still breaking the law.

    Doing 135kph down the southern motorway would seem like you are flying, whereas on a UK or European Motorway it seems like an average speed.

  11. Mike says:

    Must admit I was a bit spooked at first with the open UK motorway speed which is fast. Yes I agree their motorways are safer which I believe is not so much the physical motorway rather the driver attitude and skills.
    I cannot understand why NZ does not enforce the keep left rule on our motorways and expressways. Our motorways would flow so much more smoothly with this simple rule enforced. I wonder how much congestion is actually caused by this?

  12. damian says:


    Kiwi drivers are shocking, just look at the weaving and changing of lanes every two seconds when it appears that the other lane in moving quicker, all just to think that they are going to get there a few seconds quicker.

    Look at the slow vehicles on our roads speeding up when there is a passing lane. I feel like getting a sign saying ” if there is a big que of cars behind you, you are driving slow. Please slow down even more when on a passing lane so people can overtake, do not speed up!”

    I am not sure how you could enforce the keep left rule, most UK and EU drivers will flash their lights to ask you to get out of the way, in which they do. Here it is seen as a right to travel at what ever speed they wish in what ever lane.

    As for the physical motorway, the UK road alignments are far straighter with less tight bends, plus the carriageway widths are slightly wider too.

  13. Peter says:

    Yes, peoplemight be breaking the speed limit at 115kph on the motorway and on the open road but that does mot make someone an unsafe or dangerous driver. The speed limits on British and continental motorways is far higher than in NZ but there accident rate is far lower. Why? Because most people in Britain and Europe are taught to drive properly. Furthermore, the police enforce the keep left rule thus reducing congestion and frustration and are more concerned with the manner of driving and where it takes place Why do NZ police not enforce it, when the rode code catogorically says “Keep left unless overtaking”. They are obsessed with speed but that is NOT the problem. Ex UK policeman; advanced trained driver and motorcyclist.


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