This is a guest post by Glen Koorey from ViaStrada.

Do you know how many fatal or injury road crashes there were in 2018? No, neither did I, until I looked it up. Turns out there were 11,433 injury crashes, of which 2085 had serious (hospitalising) injuries and 332 had fatalities.

Why don’t most people know that? Because most of the public media attention revolves around the number of road deaths every year. So, it’s not surprising that many people know that this figure was 378 deaths in 2018 (or could guess something similar), although fewer might know that there was also over 2500 serious injuries that year. Either way, clearly we’d rather not have over 2900 people killed or seriously injured each year and that is the focus of our transport agencies’ road safety efforts.

Despite this, a lot of the public debate around road safety seems to end up with people suggesting various ways to reduce crashes. But this is not the same as thinking about how to reduce deaths and injuries. Obviously, there is some correlation; you have to have a crash first to have an injury of some sort. But if you’re trying to focus on how to reduce the latter most effectively, you will come up with quite different solutions from trying to reduce crashes the most.

An example might help explain this better: Consider “rear end” (nose-to-tail) crashes; in 2018 there were 1162 rear-end injury crashes. That’s over 10% of all injury crashes, so perhaps worth exploring. What could we do to reduce all these crashes? Maybe more skid-resistant road surfaces, or better visibility of things like traffic lights and hidden queues. Possibly encourage more take-up of cars with automatic brake assist, or even more education and enforcement of drivers around not following too closely.

All this effort might see a good reduction in those rear-end crashes, but let’s look at the casualties from those incidents. Most of them were minor (i.e. non-hospital) injuries; there were only 7 fatalities and 98 serious injuries. Is it worth focusing a lot of effort on this issue if we want to get our casualty statistics down?

Compare that with “head-on” collisions: in 2018 there were only 773 of those (less than 7% of all injury crashes). But those 773 crashes were responsible for 134 deaths (more than one third of the year’s total) and another 383 serious injuries.

What would help reduce the likelihood and severity of head-on crashes? Education and enforcement focus on driver fatigue and distraction might help, although it is hard to dramatically improve driver behaviour in these areas. An obvious one is more centreline median barriers, preventing encroaching into the oncoming traffic. Maybe improving the alignment, width and sightlines of some roads would also reduce the likelihood of crossing the centreline.

All those engineering solutions cost a lot of money though, so they won’t be cost-effective everywhere. That’s where lower speed limits also come into play; we have a lot of rural roads in particular where the standard 100 km/h limit is completely inappropriate for the road geometry. Slowing down traffic can greatly reduce the potential impact speed of two oncoming vehicles. Note, this is not the same as focusing on speed enforcement, often widely panned in NZ, it’s about reducing the expected travel speeds for various roads in the first place.

Let’s have another look at those median barriers. While they are likely to dramatically reduce the likelihood of head-on crashes on the other side of the road, you are equally likely to increase the number of crashes into those barriers (or even into other vehicles on the same side of the road as you). The difference however is that these types of crashes are much more forgiving than head-on ones – you are highly likely to still come out very much intact.

These UK chevron markings are another possible way to tackle rear-end crashes. But the barriers on each side of this carriageway probably do much more to tackle fatalities.

This focus on deaths and injuries rather than crashes also accepts the fact that we humans are fallible and make mistakes and poor decisions sometimes. Scandinavian and Australian research found that, even if road users followed all the road rules, fatalities would only fall by around 50% and injuries by 30%. So we need to come up with ways to prevent people dying as a result of a “simple error” by them or someone else.

Tackling road safety in New Zealand will require a multi-faceted approach; there is no one “silver bullet”. But it is important that we focus on the most appropriate treatments to reduce deaths and injuries, rather than simply what might reduce crashes.

Dr Koorey is a Principal with ViaStrada Ltd in Christchurch. He specialises in road safety and sustainable transport, with a particular focus on speed management.

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57 comments

  1. “The difference however is that these types of crashes are much more forgiving than head-on ones – you are highly likely to still come out very much intact.”
    Except for motorcyclists. The wire “cheese grater” barriers are so dangerous for us. Sure head ons are worse. And motorcycle deaths are rising.
    Aren’t there other solutions?

    1. “The wire “cheese grater” barriers are so dangerous for us.”

      No, they aren’t. It’s an utter myth that these barriers are more dangerous. It’s an even more ridiculous myth that they chop people in half. The wires are almost 50mm thick, ffs.

        1. The same way road layouts induce fear in cyclists, pedestrians and scooterers, causing them to take more care? By being flippant about the problems of a group you don’t perceive to be part of your tribe, you’re giving a free pass to petrolheads and others to treat you the same.

          Instead a fair statement would be that motorcyclists are possibly the worst affected group of all, but dramatically improving their fatality and accident rates is difficult given the speeds the vehicles are designed to travel at, and the low feasibility of separating them into their own lanes.

      1. No need to be rude!!!! And glad to be corrected. Please restrain yourself, I genuinely thought that these were dangerous for motorcyclists.

      2. Sailor Boy. Have you seen the remains of riders who have hit these wires? Seems to me such a small surface area taking all that impact comprising of soft flesh could do some spectacular injury. And I am guessing you have not seen how sharp the props are that hold them up either by your comment.

        1. I Think Sweden has done studies on the affect of wire rope barriers on motorcyclist which may be worth a read. I don’t think any of them suggest that they are “cheesecutters” . The issue really is how much momentum the rider has when he hits any barrier. Concrete barriers would not have a better outcome either as these would not move/give for the motorcyclist.

    2. I can only recall one motorcyclist who was killed (or in this case mutilated) by crashing into a “cheese cutter” barrier. In that case, the motorcyclist was traveling in excess of the speed limit. It was surely enough to instill fear among the motorcycling community across the country.

      However, they do their job, which is to keep cars from drifting off the road or into the oncoming lane. Their elasticity absorbs some of the impact reducing the likelihood of death for those occupants.

      1. and motorcyclists being in that oncoming lane, but less visible than other vehicles, are therefore helped by the barriers, too.

        1. Maybe if car drivers got off their cellphones and concentrated on driving there’d be a lower road toll. It’s high time to increase the fine for using a cellphone to something like the $400 it is in some Australian states.

        2. Agree. $80 is a pitiful penalty for an offence that causes major driver distraction. There is no excuse to use a hand held phone while driving.

    3. Some 17 or 18 years ago I was an analyst at the Ministry of Transport when these flexible wire barriers were becoming more widespread in New Zealand, and I had a job of reviewing the international data at that time. That data showed that injuries from flexible wire barriers were only somewhat different in nature, and lesser in severity than any of the alternative options, or the counterfactual of having no barrier in place.

      In effect, the abrasion injuries from wire ropes were no worse that the abrasion injuries from sliding along the road at the same speed. (I’ve slid across the road coming off my bicycle at 50km/h, and it wasn’t pretty.) Fatalities and serious injuries among motorcyclists were lower from wire rope barrier than from armco (metal W-section) or concrete barrier, and much lower than riding into an oncoming vehicle, tree, post, wall, or other immovable object. And finally, they stop distracted oncoming drivers from wandering into the motorcyclist’s lane.

    4. Shouldn’t the importance of removing direct access to driveways and houses on main roads bump the crashes one a bit more? Cars turning suddenly into driveways at high speeds, while there is a truck directly behind and/or any type of cycleway, is never a good thing. I think New Zealand needs more street hierarchy enforced by physical controls like bollards, width, surface texture, etc: https://bicycledutch.wordpress.com/2013/08/08/making-a-1960s-street-grid-fit-for-the-21st-century/

      Reducing crashes is a subset of reducing injuries and deaths. A VERY important subset.

  2. A good way to reduce head on collisions is to create more passing lanes/slow bays and to actually enforce the keep left unless passing law far more rigorously than at present. Quite simply if people can pass more easily, safely, and frequently then there is a little incentive or need to overtake where it is less safe to do so thus avoiding a huge amount of head on collisions (and fatalities).

    1. Completely agree about adding passing lanes on busy rural roads. However, adding passing lanes that require you to build a road with no shoulder, building passing lanes through intersections, and building passing lanes that are too short all increase fatal collisions. We need to place *good* passing lanes, which is expensive, so needs to be targeted.

    2. I thought the most common case of head-on collisions is where someone just drives his car off the lane for no apparent reason — either into the ditch or into oncoming traffic.

      1. Isn’t a head-on collision if crash is into a ditch. Head-on is between a vehicle and another vehicle travelling in opposite directions.

      2. Ok that was an unfortunate way of saying it. I thought going into the ditch, or going off your lane (not overtaking) and crashing into oncoming traffic are both more common than crashing while overtaking.

  3. Here again we have a professional who cant see the wood for the trees. Look at crash rates on divided highways versus non-divided. The accident rate plummets. Barriers DO work!

    1. Here again we have an amateur that can’t read. Glen quite clearly states that ‘An obvious one is more centre line barriers’.

      1. I think the objection is to “Let’s have another look at those median barriers. While they are likely to dramatically reduce the likelihood of head-on crashes on the other side of the road, you are equally likely to increase the number of crashes into those barriers (or even into other vehicles on the same side of the road as you).” The “equally likely” suggests crash rates are the same.

        1. Yes, and given Dr Koorey’s knowledge of the subject (he was a lecturer of mine) I’d trust he is exactly right with that assertion. It makes sense that accident rates are the same, people are still just as likely to loose control, the big change is the severity of the accidents.

        2. Glen used the barriers as an example of a good device because it reduces DSI whereas focusing on reducing crashes may not have prioritised the barriers; those stats presumably being less significant than the reduction in DSI stats.

  4. There’s a lot of old cars on the road in NZ, the average age of our passanger fleet is over 14 years, if we could reduce the average vehicle age we would also see a corresponding drop in accidents with severe injury or death. Newer cars are inherently safer than older cars in accidents.

    After a pretty server accident 11 years ago I now buy a new family car every 3-4 years. Keeping my family safe on the road is my responsibility and I take it seriously.

    1. Yes, I agree the age of our fleet is a problem in some ways, and it seems that this isn’t going to change, given the economic position many are in. The other problem is that the new cars have been designed for the car occupants’ safety at the expense of other road users, for example with wider front pillars which restrict visibility. It may be that people should hold onto their 14 year old hatchbacks than to buy an SUV, if we are to make decisions not just for our own families but for all road users.

    2. Agree, I take a similar approach with cars. Although the laws of physics catch up even with new cars once you go above 80kmh.

    3. I’d like to think that keeping your family safe on the road is every road users responsibility, and that they are taking it seriously

      1. A lot of people don’t, I always see kids in cars unrestrained or loose dogs running around. Our 55kg pup is always restrained in the back.

    4. Not many are in your financial situation though. Keeping my family safe on the road is something I take seriously too, and I drive much slower with my infant child in the car.

      1. …but once the error is made (and, being human, they will happen) you will wish that you had a good quality car, good quality road, or were travelling slower. The first two take time to get a noticeable change in our vehicle fleet or road network, but speed reduction can be done relatively quickly.

        1. +1 And the last one can also be provided for people who can’t afford new cars, so it is more equitable.

  5. Cars have to meet increasingly stiffer crash tests, blame the legislation not the manufacturers.

    That said I take the safety of my family seriously, so long as I come out ahead in any (not my fault) accident I’m happy.

    The accident I had 11 years ago could have been a nasty one if our car wasn’t as good as it was, it was a 6 mount old Mercedes C Class Touring, we stopped behind a turning car, the guy who hit us from behind was travelling at an estimated 80kph in an older Hyundai SUV, he crushed his ribs, punctured his lungs and ended up in critical care, my wife was 9 months pregnant so was taken to hospital for observation overnight and I had a stiff neck for a couple of weeks.

  6. I really don’t know the data so I’d be interested to see it, only know anecdotal quotes of how SUVs are safer for the person in the car and worse off for everyone else, including the Climate. So why on earth do we have this obsession with them in NZ. I understand Farmers and Tradies requiring them for work, but the whole argument that you need them when you have a family, despite the average family size dropping across the world and SUV sales going up.

    So, when I see single occupant SUVs rat running down Ponsonby Roads I wonder what we can do to try and lean ourselves towards a more fuel economical, pedestrian and driver fleet.

    Prob points to consider would be

    – Congestion Charging
    – Reclassification of SUVs (require additional license)
    – Higher rego to pay for additional Road Safety.

    Like I say, I don’t know enough about the data, just know that down the line society really needs to look at why we need these massive things on our Roads.

    1. Safer for the person in the car → there you have it. Why do people buy SUV? “Only the other guy will die.”

      There are other reasons like seating or storage, but if that is the issue then a van will be completely superior.

      Then there is towing capacity. There is a reason why these things are sometimes called Remuera Tractors.

      I’d also love to see a reclassification. If the bonnet is almost as high as an adult it really should not be called a “car”. Then again the definition over here is very, very liberal. (see https://www.hireace.co.nz/Vehicles/trucks.html, which mentions you can drive these with your car license)

      And, not unique to New Zealand. See https://www.andrewalexanderprice.com/blog20121102.php for a rather entertaining take on this.

      A long time ago it was still OK to mock people buying SUVs. A blast from the 90s linked below. Now dominance of SUV in new car sales is so total that some car makers (Ford, and I think also Nissan a decade ago already) just no longer produce traditional sedans anymore.

      Canyonero. https://www.youtube.com/watch?v=7ZeFDe44Ddo

      1. That Canyonaro jingle pops into my head every time I see an oversized SUV… It’s increasingly a constant soundtrack to my commute.

    2. “So why on earth do we have this obsession with them in NZ”

      From what I understand, it’s like House and Garden trends… we follow the US. And they prefer the SUV’s because they don’t have to meet the emissions standards that cars have to meet, being work vehicles. Which should clearly help form our emissions standards – no exceptions for work vehicles.

      1. But that’s only in North America, the SUVs (and cars) we buy are generally built to Australian market specifications where emissions and crash testing is mandatory.

        1. Thanks. I noticed the emissions of new vehicles into NZ improved until about 5 years ago, and haven’t changed much since then. I intend at some stage to look at the different categories. Obviously heavier cars will have worse emissions ratings than lighter cars, in general. Do the Australian emissions standards put the SUV’s we’re importing into the same category of vehicles of a similar weight?

          The crash stats for SUV’s with pedestrians are appalling… needs a blog post.

      2. That’s not true for many US states, particularly California. Vehicles that don’t need to meet mileage requirements are the so called three quarter ton trucks and up (eg Ford F250 and larger, Ram 2500 and larger etc). The half ton trucks (eg the Ford F150, Ram 1500, GMC Sierra 1500 etc) must meet standards. I don’t believe any SUVs are exempt from the standards.

  7. The problem is the mindset of NZer, they always think they are the God, they do better than all others, as a result 1. wrong road was designed. 2. They drove faster than it should be. 3. They accepted more than affordable people into NZ.

  8. NZ needs to:
    1) Commit to vision zero as a policy (Government seems to be looking at it)
    2) Then implement a new nationwide infrastructure standard consistent with that policy
    3) Require all new works and retrofits to meet that standard.

    Where I currently live the roading design is inherently safer and much closer to a vision zero design, for example:
    a) all cycle facilities are off road
    b) all traffic signals have approach based fully protected phasing, i.e. no filtering turning traffic
    c) pedestrians and cyclists have fully protected phases at the signals.
    d) priority cross junctions only exist on local streets, speed limit 40kmh. There are almost no priority junctions on the main road network. Where they do exist there are speed humps often on all approaches.
    e) At signals the green signal flashes about 3 times before going amber. This reduces the dilemma zone. It does increase rear end crashses but also reduces right angle crashes within the intersection
    f) high speed roundabouts have speed humps on their approaches and are traffic circles with no deflection
    g) there are speed cameras on the highways every 5km
    h) where there are roadworks often thick transverse yellow rumble strips are laid down
    i) Almost all the highways are median divided and plans exist to median divide those that aren’t.
    j) There is no parking on the main road network. Yes traffic moves a little faster without it, but it is one less distraction & slight lines are much clearer.

  9. “Education and enforcement focus on driver fatigue and distraction might help, although it is hard to dramatically improve driver behaviour in these areas.”
    An area that is currently an issue is the ease of taking breaks to deal with fatigue. On many roads and highways there is nowhere that feels safe to stop and take a nap. Most current rest stops are not what most people would consider safe to stop and take a nap at night. This leads to decision making of paying for a hotel for the night or pushing on to get to the destination, most people will make the second choice. Why is there not a push for places for people to stop for a couple of hours to stop and reduce fatigue”?

    1. +1 A couple of years ago I drove the coast from Sydney to Melbourne and every 50km or so there was a small rest area. Just a covered picnic table and a public toilet at most of them. It made me much more likely to stop and have a break from driving!

  10. Shouldn’t the importance of removing direct access to driveways and houses on main roads bump the crashes one a bit more? Cars turning suddenly into driveways at high speeds, while there is a truck directly behind and/or any type of cycleway, is never a good thing. I think New Zealand needs more street hierarchy enforced by physical controls like bollards, width, surface texture, etc: https://bicycledutch.wordpress.com/2013/08/08/making-a-1960s-street-grid-fit-for-the-21st-century/

    Reducing crashes is a subset of reducing injuries and deaths. A VERY important subset.

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