Written By:
Bill - Date published:
12:21 pm, March 17th, 2011 - 39 comments
Categories: disaster, transport -
Tags: cars, disaster, tsunami
Reports from up and down the coast of Japan have commented, almost as an aside observation, that the roads out of towns were essentially gridlocked as the tsunami approached. Now I’d guess that a lot of people will conclude that roads came to a stand still because somewhere a building had blocked the road, or a car had broken down at the head of the traffic or because of some other external factor. In other words, that the people trapped in their cars were unlucky; that they had given themselves the best of all chances to escape but had been foiled by circumstances beyond their control.
But that’s very far from the reality.
See, if you receive a tsunami warning, you might intuitively jump into your car reasoning that it’s your best chance of out running a 60km/h wall of water. And there’s only one flaw. In the situation of a town evacuation, the moment you jump into your car to escape you more or less guarantee that you will die.
While it may be the case that some roads become impassable due to physical barriers, it will make no difference to the efficacy of escape by car if there are no obstructions and no broken down vehicles blocking the roads. And even if the total volume of traffic doesn’t exceed the carrying capacity of the roads, traffic will come to a stand still and people in cars will be going nowhere as the wave hits.
A study was conducted on this phenomenum. Researchers were curious as to why motorways often came to a standstill even where there are no road works, bottlenecks or accidents. The study found that if the volume of traffic is heavy enough (ie, if the actions of the car in front elicits a response from the car to it’s rear…as like in a mass evacuation) and somebody travelling at 100km/hr applies their brakes for a split second, then that will unleash a momentum of deceleration travelling back through the column of traffic that will result in traffic coming to a dead stop.
And as we all know from sitting even just six or seven cars back from a green light, a time lag comes into play when we are looking at getting a stationary column of traffic moving again. Meantime, if somebody towards the front of the column accelerates a little too quickly and has to touch their brakes…
It’s pointless to speculate on the numbers of people who died unnecessarily because they put their faith in a car as being the fastest means of escape. Sure, some might have had enough time to get to safety by foot or bicycle. And for some there would have been no possible means of escape no matter what.
But it’s worth noting out that in the case of a reasonably sized population looking to get itself away from a tsunami, that a car offers no means of escape at all and instead becomes, quite literally a death trap.
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yup. roads just clog in a panic, and main ones tend to follow the path of least resistance up valleys, just like the water will. you’re probably best to run for the closet high point on foot – a hill or a large steel/concrete building.
and don’t think just because you’re over 10m elevated that a 10m high tsunami can’t get you, it’ll wash up a hillside – check out this vid
Agreed. A slight momentary disturbance on a packed but moving road will rapidly bring the whole back half of the traffic to a dead stop.
At very busy times in NZ the passing lanes are closed off because of the factors you describe. Seems to be daft but constantly flowing traffic at a slower speed is better that brake/hesitate/slow/go.
One of the helicopter tsunami views showed a dozen cars stationary at an intersection with the flood approaching from the right. One car started moving and turned left and away. But I found myself willing the other cars to move, move. The clip then ended. Haunting.
ianmac, on TV7 recently there was an excellent documentary on traffic and the stop-start flow and the conclusion echoed yours in that slower moving traffic often moves much more efficiently. The stop-start phenomena was compared with a plague of locusts jockeying for position against the steady and uniform procession that ants and fish tend to favour.
Also a town in the Netherlands was profiled where there weren’t traffic lights but many roundabouts and the change in accidents and fatalities was marked. The premise was that people were such much more careful of other motorists, pedestrians and cyclists because they had to read facial expressions and catch each other’s eyes in order that everyone’s safety was preserved. The reporter was completely flummoxed that this apparent lack of order in fact increased people’s safety.
It was delightful to actually watch something worthwhile, informative and thought-provoking for a change.
If I recall correctly in some European towns they removed all existing traffic lights, and the number of accidents plummeted.
Amazing what happens when you force people out of their auto-pilot world.
I’ve also seen footage of crowded museum floors or train platforms – hundreds of people moving in different directions, successfully making little course and speed changes, avoiding crashes and smashes with each other, without even thinking about it.
Not just that, either. I found in many cities in NZ, the lights were well co-ordinated. I could sit at the top of Queen St and, provided I did the limit (and the traffic was light enough to permit me to do so) I would see the lights in front of me turn green sequentially and I could get all the way to the bottom without stopping. Therefore I happily obeyed the limit.
Over here in WA, where the government assumes its citizens are drooling lunatics who, left to their own devices, will happily drive over hand-holding schoolchildren on a crossing, they phase the lights so they stop you every few metres. So you sit at one set and see the set in front of you go green, but you can’t go. Then you get a green but the set in front are going orange.
So some people slow down, accepting the stop-start nonsense as a cost of living here, while others speed up to try and actually get 100 metres or so in one push of the accelerator.
Meanwhile, a driver heading across the intersection anticipates the green light he’s about to get by a millsecond and starts to cross and… bang.
Sometimes it’s driver inattention. Sometimes it’s driver frustration with traffic authorities’ stupidity.
Either way, roundabouts are definitely better (unless you’re in Hamilton, where I saw an old man in a hat hestitate, then go counter-clockwise, presumably because he wanted the exit immediately to his right :-/ )
There’s a lot of that timed stopping of traffic in Auckland too. Often it means queues of traffic are sitting staring at each other for a long time, with no-one able to go. What a waste of petrol & time!
yeah i saw that no traffic lights worked,it was cool
I would love to hear your alternative means of escape.
The trains would have stopped as soon as the earthquake hit in case they tracks were damaged, they were parked up for days around canterbury and running miles in some cases inside half an hour is beyond most people, esp if carrying children. And how high is high enough?
I’ll happily wager that many more people escaped in cars then were killed in one, and those that did die were screwed anyway.
Try reading the full article.
Its hard to find out how much warning people had before the tsunami hit the coast of Japan.
Was it 15 mins or was it an hour?
If it was the former, there wasn’t much a lot of people could do. If it was the latter, relatively few people should have perished.
I listened to a report where a survivor said there was a warning of a potential tsunami about one minute after the earthquake and a second warning of a definate tsunami aroound one minute later.
I don’t have the figures to hand, but a tsunami moving at 500-600km/h and slowing as it came into shallower waters and that originated at x distance would take how long to hit?
It’s all kind of academic though. Living in a place like Christchuch, as opposed to a Wellington, would afford you bugger all chance of escape.
And I’d guess that Japan is composed of a similarily widely different topography.
Living in a place like Christchuch, as opposed to a Wellington, would afford you bugger all chance of escape.
IIRC Wellington has a high risk of seiching within the harbour, and the potential impact is greater than the likely impact from a tsunami outside the harbour. Due mostly to the bathymetry of the harbour and especially that the mouth of the harbour is comparatively shallow. Seiching can start so quickly that warning systems are ineffective.
Christchurch – tsunami – yes, very little chance of escape. Survival would come down to luck.
And I’d guess that Japan is composed of a similarily widely different topography.
There has been a lot of reclamation in Japan. Tokyo Bay alone has almost 100sq.km more reclaimed land than the total area of the old Auckland City (i.e. from Herne Bay to Onehunga, and from the Whau to the Tamaki River), volcanoes and all.
Reclaimed land is susceptible to tsunami risk, by definition. Allowing high population densities on large areas of reclaimed land can only be considered to be a planning failure.
Buses.
Buses can take up to fifty people – roughly, at one person per car that equates to half a kilometre of traffic removed from the road.
capcha – “flew”
Normally I’d agree that if transport is the problem – public transport is the answer. But in this case it would take more than 30 mins to roster the drivers.
I think this is essence of Darwinism – survival of the physically fittest, least encumbered, smartest and luckiest. Spooky how much like neo-liberalism this sounds, although the richest doesn’t come into it. If the happened in NZ the richest who weren’t the smartest would be first to suffer- living on the coast and all that – and as Bill explains those fast cars won’t get them anywhere soon.
Hi Rosy. Not if they were already on the road.
.
Could Auckland be evacuated in an emergency?
If what happens every holiday weekend is any indication, there is no way.
Could buses do it?
At present Auckland, a city of a million, or so people, is served by 800 buses.
So on the surface of it, this also would be inadequate.
But if the $billion earmarked for Auckland’s motorway expansion, was instead switched to expanding the bus fleet, Auckland could have over 3,000 brand new, low emission buses and run them fare free, 24/7 for thirty years, running to every corner of the city.
In a disaster if given priority over private cars, ie cleared lanes on the highways. Then in the first hour, using these buses, 15,000 people could be moved beyond the city limits. With a return trip, 15,000 people could be evacuated every two hours.
Buses with their huge fuel tanks can run continuously for days without refuelling.
Obviously for sudden disasters with little warning even this would be inadequate.
But with any sort of approaching disaster that had any sort of lag time, ie hurricane, or Tsumani with a distant epicentre, or even slowly building volcanic emergency – buses would indeed be the most efficient method of evacuating a city.
For further info check out Fare Free New Zealand.
I agree with you totally for all the other emergencies you mention, just not when you’ve got 30 mins lead in time. I’m a pessimist on this one.
For an even quicker response in an emergency, all buses, which as a rule are already connected by radio, could have an emergency hailing frequency, to alert their drivers. Police on the same frequency would be directed to clear their route.
With centralised direction and best information the safest destination would be communicated to all the bus drivers and police escorts.
If a major disaster was about to hit, trying to leave town in our cars will jam all the roads out of city within minutes.
All the people in the jammed cars will be forced to pull over and abandon their cars. Wouldn’t it be great if we could all get aboard the passing buses, with a police escort to clear the way.
Might depend on the circumstances, but my little (mountain) bicycle might be handy as a getaway vehicle.
Not as handy as a motorbike though, especially over broken ground requiring a little more power than average.
It does depend on the situation, as I indicated above. I have spent many years in the past driving both motorbikes and bicycles. When I lived in London, I found that it was easier to get to work on my bicycle than on my motorbike after a big dump of snow. Motorbikes are very dodgy over slippery ground, although using one’s feet/boots as stabilisers helps. Bicycles have the added advantage that they are easier to wheel or carry over obstacles and extremely rough ground.
It’s a nice fantasy to imagine that you will be able to escape past everyone else on your motorcycle, or bicycle.
But what if you weren’t near your motorbike or bicycle?
(Which under normal circumstances would be most of the time.)
Would you try to get back to it?
And if you did get back to it, would you know where to go?
Or would you be better off on the nearest emergency bus, with an experienced driver in contact with the authorities? (remembering that with a much expanded service they could be city wide, 24/7.)
It all depends on the circumstances and the quality of the roads after whatever disaster. If loads of people are capable of getting to their cars after a disaster, they are equally capable of getting to their bikes or motorbikes. Furthermore, after a disaster, a bicycle would be handy if there were any petrol shortages. A bus maybe a good way out, but I wouldn’t count on it in the face of any kind of disaster.
If I was working in Auckland CBD at the time, I’d probably have no choice but use public transport, as that’s how I travel in there. If I was out west, working or at home there…. well, buses are not all that reliable, or readily accessible to all areas. If I was at home, or fairly near there, I’d jump on my bicycle.
But Carol there is no reason at all why this should be the case. For the same projected spend on motorways, Auckland could have 3,000 brand new buses and run them fare free to every corner of the city for 30 years.
Compare this to spending the same amount on motorways, which seem to clog up as soon as they are built.
Where this has been tried overseas, tens of thousands of commuters voluntarily abandoned their private cars in favour of the free bus service. The existing motorways were left relatively empty, even in rush hour.
When I saw the title I thought it might be about cars killing society, or cars killing the planet (which they are, of course)..
No such luck. Kar kulcha is sacrosanct in NZ.
Fuel will soon be too expensive for most people to afford, so we won’t have to worry about the role of cars for much longer.
Come on Brain, I know you can do it.
Rather than just telling us the problem.
How about offering us a plan.
Depends very much on the circumstances.
In some cases walking, running or biking are the best option, and cars are deadly.
In other cases it’s not possible to evacuate quickly.
Auckland, for example, would take days to a week to completely evacuate by car.
I’d hate to think how Wellington could be evacuated.
The long term solution is either expensive protection works, or relocation of the town or city (voluntary or compelled by nature) and acceptance of the risk in the interim.
The post isn’t about days long or weeks long evacuation. It’s point is that in a mad dash rush, our initial and intuitive option is potentially the worst of all options.
Yeah, I got the point of the post, Bill.
It’s pretty difficult to disagree with, so rather than try to disagree I thought I could try to explore related subjects. Like how trying to escape impending disaster in a car can be a bad option in other types of disaster, or how in some locations it may well be difficult to to get to safety at all. Hope that’s okay by you.
IMO the best solution is to completely avoid the need for the mad-dash rush. This will be difficult, for sure, but it’s far from impossible.
Surely a truly “intuitive” response is still to run for it not jump in the car.
My understanding is there was 30 mins from earthquake til when the tsunami hit. I could definitely walk to higher ground in less than 30 mins here in Welly
Agreed feijoa. Except would you really believe that there was a significant tsunami coming? In hindsight………..
Since they lowered the speed limit to 80kmh and made the coastal highway near Paekakariki one lane each way, the traffic along there moves much more easily too.
An 80km limit as opposed to a 30 or 100 km limit would make absolutely no difference in an escape scenario.
There was some footage shot from helicopter last Friday of a convoy of cars (a dozen or more) heading inland to evade the tsunami, which was catching them at a decent rate (maybe 50% faster tops?), only for the camera to break away before engulfing the car at the back of the convoy. I remarked to my partner, that the Japanese news coverage showed a lot of respect for their citizens by breaking away from what likely to become a tragedy. These particular cars were probably doing the speed limit, and all the time the opposite lane which was completely empty. It probably says a lot about their culture of being law abiding, conformist, having manners, safety and respect?
I just hope that none of them got caught up in natures version of a front loader wash.
Issues in escaping a tsunami by moving inland like this have led to suggestions that ‘vertical evacuation’ is the more appropriate, i.e. evacuating up tall buildings or structures. Definitely worth keeping in mind if the situation ever occurs. As with many such things, the most intuitive means of escape is not necessarily the best.
Yes certainly, if the building chosen was tall enough and built strong enough.
However many of the areas hit in Japan seemed to be fishing villages and small towns. Not much over 2-3 stories.
Indeed. It might be worth considering building such structures in tsunami prone areas, if the population density warrants it. (reply to CV above)