This is not completely unheard of. Just a few weeks ago, the Wellington council voted to reduce the speed limit to 30km/h on 80 per cent of city streets. Again, it was an idea pushed by Waka Kotahi - which has control of roads outside council areas.
And so it will be the Christchurch City Council that makes the final call here - but Waka Kotahi and senior government ministers are pushing the idea big time.
And as we know - generally, what Waka Kotahi wants, Waka Kotahi gets.
It's just a pity they don't want more critical things like median barriers on as many roads as possible. But then forcing - sorry, encouraging - the local council to reduce local speed limits to 30km/h is the easy option, isn't it?
Now you might be thinking, "I never get to a speed any quicker than 30km/h on some of those roads they're talking about". But there will be roads and streets where 30km/h is just not practical. And there are times when you can go faster on those main roads I mentioned.
All of this is part of the Road to Zero campaign. And Waka Kotahi is citing an OECD report from 2018 that says if someone is hit by a car travelling at 40km/h, the probability of them being killed is double what it is if the car is doing 30km/h.
And if the car's doing 50km/h, then the chance of surviving is even less.
But sometimes when a person or an organisation comes up with an idea, you've just gotta say "yeah cool, but…".
And this is an example where I just have to say "yeah cool, but…" for a couple of basic reasons that I don't think anyone at Waka Kotahi thought about when they were sitting around the whiteboard doing the old brainstorming session.
No one is going to argue that minimising the risk of death for someone hit by a car is a good thing. In fact, it's not just a good thing - it's a critical thing.
But do you really think reducing the speed limit on paper is going to make one iota of difference? Of course it's not.
That bozo you saw at the weekend in the Nissan Skyline doing 80km/h in a 50km/h zone: they're not going to give a damn about the speed limit being 30km/h are they? And do you really think the police are going to be out there pinging people for going faster than 30km/h?
We never seem to have enough cops on the roads to police the 50km/h and 100km/h speed limits, so what makes Waka Kotahi thinks this is remotely enforceable?
Well, it's not. This shows why this Road to Zero thing is pretty much about strategy documents and plans, and ideas that sound good but achieve nothing.
And it's not just Road to Zero. I remember the National government had its own version back in the day - it was called the Safer Journeys Strategy. You still see the Safer Journeys logo on some of the road signs around the place.
I remember talking to the Associate Transport Minister when National was in power and him trying to convince me that it was working - even though the road toll was going up. Again, looked good on paper, but didn't achieve much.
And, as I say to the teenagers who have all now got their full licenses, a 50km/h speed sign or a 100km/h speed sign doesn't make that speed compulsory, and it's all about assessing what's going on and driving to the conditions.
That's why I think a blunt instrument such as saying "right, pretty much on every road in Christchurch the speed limit is now going to be 30 or 40km/h'. I think forcing that on people is a feel-good but no-good kind of thing.