Rail Crossings Might Have Prevented Some Cars From Evacuating on 3/11

[gmat]

NHK had a report on the News tonight. Apparently the Earthquake might have cut off the power to the crossing gates, where upon the gates automatically came down and blocked the roads. So apparently many fleeing drivers were reluctant to drive through the barrier poles and were caught by the following tsunami. Some points brought up include; 1. rail lines to be reconstructed might be graded to allow traffic to move freely, 2. some municipalities are planning to make changes to roads to avoid the same problem, and 3. other rail lines that run near the coast throughout Japan could face the same risks.

How about the area that was considering bus lanes to replace local rail lines? Hope they reconstruct the rail lines instead.

Best wishes,
Grant

[westfalen]

Just shows how much the average Japanese motorist respects level crossings, even faced with a life and death situation they won't drive through.

[Mudkip Orange]

Yeah, that's crazy.

Stop for crossing gate with no train in sight? Or, ALMOST GUARANTEED DEATH FROM ONRUSHING TIDAL WAVE.

Decisions, decisions...

[KenS]

I think it's more likely that the decision process was "stop for a gate warning me of a potential train, a threat I see every day, or go for a siren that tells me a big wave might hit the coast, and might if I'm really unlucky, come this far and get my tires wet?".  It's well known that people don't evaluate threats on real risk, but on criteria based on experience of them and other subjective factors. Given the decades since the last devastating tidal wave, few of the drivers would have had any experience of one on which to base their decision. All it takes is one cautious driver to stop traffic. And once a row of cars is stopped, its not going to restart fast enough when the wave itself is seen to get most of the cars to high ground. By the time the tidal wave was "real" to the drivers it would have been too late.

To me, the interesting question isn't "why did they stop?", but rather "how do you make this system work against both threats?".  Grade separation may be the only solution if you want the gates to "fail safe" and come down when communications lines that warn of an oncoming train are broken (e.g., in an earthquake).  One possibility would be to build seismogaphs into the gate controls (you can get an accelerometer on a chip today), and disable the "if no communications lower the gates" logic for an interval after a quake, counting on the fact that the same quake is going to bring the trains to a halt.  There's still risk (a train doesn't get the stop warning, the lines are broken and the gate doesn't know a train is coming, a car crosses or stops on the track at the wrong time and gets hit). But you've balanced the two risks a bit better.  That won't work if the gate control itself is damaged or loses power in the quake though. But with a more robust control system, it might be more practical for smaller, less-frequently used crossings on escape routes, than expensive grade crossing separation work.

[clem24]

Just shows how much the average Japanese motorist respects level crossings, even faced with a life and death situation they won't drive through.

No no, *this* video takes the cake in terms of respect:

<a href="http://www.youtube.com/v/IQqmp9OOE1E" target="_blank">http://www.youtube.com/v/IQqmp9OOE1E</a>

Skip to about 0:50 and watch what the guy does after getting out of his car when the tsunami hits.