It’s not quite as fast as Selwyn mayor Sam Broughton wants it. But the Government’s thinking about raising the speed limit on the Southern Motorway between Rolleston and Christchurch to 110 kph per hour - which would be the highest speed limit in the South Island. 

Mayor Broughton reckons it should be 120, the Government thinks 110 is more like it, and I think it should stay at 100. 

The mayor’s argument in favour of increasing the speed limit seems to be along the lines of ‘people are already driving that fast now, so that’s what the speed limit should be’. 

Which is a bit like saying, ‘some people are murderers, so let’s make murder legal’. 

I know, slight exaggeration, but that’s why the mayor of Selwyn wants to see the speed limit lifted - because people are driving fast, anyway. 

Transport Minister Simeon Brown, though, reckons it’s all about productivity. It’s about getting stuff done. 

Here’s what he has to say about that: “Boosting economic growth and productivity is a key part of the Government’s plan to rebuild the economy. This proposal supports that outcome by reducing travel times and increasing efficiency on this key South Island freight route. 

“The Christchurch Southern Motorway has reduced congestion, and improved safety and travel time reliability.  

“We know how critical this connection is for motorists and freight operators, and we’re committed to ensuring that this state highway enables people to get to where they want to go, quickly and safely.” 

Which all sounds great, Simeon. But how much quicker do you think increasing the speed limit is going to make things? By my calculations, if you compare a 100 kph speed limit with a 110 kph limit —and if you drive at those speeds— the faster speed takes just over a minute off your travel time. 

Is that really worth it? I don't think so at all. Especially when we know that the faster a vehicle goes, the messier things get when they crash.  

The other thing that makes this such a daft idea is the fact that it was only three months ago when the Government pulled the plug on a $90 million upgrade of Brougham Street, which would have to be one of the most congested and dangerous roads in the city. 

It was due to be underway by the end of the year and would have meant there’d be an overbridge for pedestrians and cyclists, lanes for car-pooling and buses and motorbikes, and a shared pedestrian-cycle path.  

But because that’s not happening, this “critical connection for motorists and freight operators” that Simeon Brown is going on about, will continue to come to a standstill as soon as it hits Brougham Street. 

So, if this speed limit change goes ahead, you’ll be screaming up the Southern Motorway from Rolleston, you’ll get to Brougham Street and then you’ll be going nowhere fast. 

You’ll get there a minute quicker. But so what? 

The other question this raises, is if it’s good enough for the Government to be thinking about raising the speed limit on the Southern Motorway, should it be doing the same on the Northern Motorway? 

Here’s why Simeon Brown thinks the Southern Motorway is ripe for faster driving. He says “the Southern Motorway was built to a high safety standard and has delivered strong safety benefits for people travelling in and out of Christchurch. 

He says that the Southern Motorway has “safety features that greatly reduce the risk of death or serious injury in a crash, including two lanes in each direction, flexible median barrier between opposing lanes, and a smooth alignment that offers good forward visibility for drivers.” 

So, even though I’m against this idea of increasing the speed limit on the southern motorway - if the Government ends up doing it, then they might as well do it on the northern, as well. 

Because if it reckons the southern is safe enough for faster driving. Then the northern must be too, right?