It’s not four lanes, but Waka Kotahi is planning to widen State Highway 1 between Ashburton and Rolleston.

The move has been given the tick of approval by Ashburton Mayor Neil Brown, who sees it as a better option than installing median barriers.

Brown has taken to playing a song at the start of each council meeting as councillors settle into their seats.

Last week he went with ACDC’s Highway to Hell, a not-so-subtle nod to Waka Kotahi’s relationship manager James Caygill being in attendance to discuss the SH1 improvement plan.

That plan now centres on widening the existing road corridor as the first step.

“Crossing a centre line is probably the biggest risk people face,” Caygill said.

“When you are travelling at speeds of 100kph and you are divided by a painted line, things go wrong.”

The solution is a progressive widening of SH1 to be able to establish wide centre lines to keep vehicles further apart, and then if required, the flexible barriers.

The stretch of SH1 from Ashburton to Templeton is a key strategic route with high traffic volumes and a poor safety record, Caygill says.

The traffic volumes are continuing to grow which is why Waka Kotahi is looking at improved safety measures.

The focus so far has been on the northern half, from the Rakaia Bridge to Templeton, because its crash statistics are much worse, Caygill said.

Police figures show that between the Rakaia Bridge and Rolleston there were 21 fatalities and 67 serious injuries between 2013 and 2022.

Brown has been a vocal opponent of median barriers and said the widening “made more sense”.

“Widening first and seeing how that goes is a good solution and then only looking at median barriers if required, and only looking at places they would be required.”

The road is currently between 7.5m-9.5m wide with plans to widen it to 11.5m, Caygill said.

“That allows us to then come in and move the traffic lanes and produce a wide centre line.”

The next step would be to place median barriers where they are appropriate and won’t impact access.

“Theoretically, we could put [median] barrier in on a narrow corridor but if we do that, then you are never going to get past agricultural vehicles, emergency services vehicles are going to get stuck, all of that.”

In the meantime, other safety improvements are being put in place with the reduction of speed through Rakaia to 50kph, across the Rakaia Bridge down to 80kph, and a variable speed limit over the rail bridge between the new weigh stations all set to come into effect later this year.

By Jonathan Leask