By Eric Crampton 19/06/2019


Navigating post-earthquake Christchurch was tough.

Every day brought a new set of road closures to route around. And they weren’t always easy to predict in advance. If enough roads were closed on the south side of town, I’d want to take the longer northern loop to get from New Brighton to the University – but I wouldn’t know that until I hit the closures.

So I’d then asked some friends at Google whether this couldn’t be automated (and posted on the basic idea here). Traffic flow data already held could be used to infer road closures. If everyone who’d been recommended to follow Dyer’s Road down to Ferry Road took a turn on Linwood instead, and nobody was on that small stretch of Dyer’s Road, it would be a safe guess that it was closed. Why not flag it as likely closed, route around it, then update when it noticed traffic flowing again?

It wound up being more complicated than I’d have thought, and SCIRT was doing its best anyway to try to get road closure data up in real time in format that could be read automatically. But it still wasn’t great.

CityLab reports that it’s coming: Google is adding a disaster-navigation tool to Google Maps. Crowdsourced user responses will provide suspected closures in addition to the confirmed road closures.

I hope Wellington does not get its expected earthquake any time soon. If it does, this will make life a little bit more manageable. There will be so many unpredictable road closures due to slips. If you’re home and have little gas in the tank, it will be hard to tell whether you can even get to the petrol station. This will help.

If the New Zealand government had put out an RFP for this kind of functionality, it doubt anyone would be offering to provide it for cheap. Instead, Google’s giving it to us for free.

I hope that, come the quake, Bernard Hickey remains true to his principles and boycotts this excellent free service.

It’s so nuts that New Zealand’s looking to move out of step with the OECD on international tax and impose punitive rates on Google. Imagine if Google ever shrugged.