110kph motorway: Save 51 seconds of travel time, but spend 4% more in fuel

Saturday, 7 September 2024

The Press spoke to people of the streets of Christchurch about how they feel about the 51 seconds saved by changing the speed limit to 110km/h on State Highway 76.

If you saved 51 seconds on your morning commute, what would you do with it?

Transport Minister Simeon Brown says that’s how much time an average driver would recoup if the speed on Christchurch’s Southern Motorway was increased to 110kph.

It’s pitched as a boost to economic productivity, which could mean a few more emails are sent, tradies can get to their sites faster, and packages might arrive slightly earlier.

However, transport planner Dr Glen Koorey said the faster speed will mean fuel costs and emissions will increase by at least 4%, which undercuts the time-saving benefit.

“Best case scenario you’re talking a 51 second saving, but that’s often not going to be the case if you’ve got traffic in the way, and there’s a fair chance there’s other things that are going to hold you up.”

From left, Pari Hunt, Te Aporei Whakawhanaunga ā Tiriti, public servant Tara Hohaia reflect on their morning commutes.

Based on 38,000 motorists using the highway each day, totting up the numbers to argue that 538 hours would be saved still only equated daily to 51 seconds per person, transport expert Professor Simon Kingham said.

Daily commuter from Rolleston, Pari Hunt, Te Aporei Whakawhanaunga ā Tiriti, said he’d use that time to connect with his whānau.

“I would probably ring a mokopuna that I haven’t spoken to for a while.“

On Cashel St, real estate agent Samantha Meads said she’d spend the seconds with her kids or cleaning the house, but didn’t think the extra time would be worth the cost.

Josh Kelly, the venue manager at Fat Eddie's, said a 51 second time-saving wasn’t enough to make a difference.

Josh Kelly, the venue manager for Fat Eddie’s, said 51 seconds didn’t give much time for productivity.

“Can’t really do much in 51 seconds, maybe walk to work from your car that you paid [to park].”

Brown said the proposal to increase the speed was designed to boost economic growth and productivity by reducing travel times and increasing efficiency on the “key South Island freight route”.

Christchurch Southern Motorway (State Highway 76) showing the exit to Curletts Rd.(File photo)

But Tara Hohaia, a public servant who takes the bus to her Christchurch office from Rolleston - said the speed increase wouldn’t impact her.

Heavy vehicles such as buses and freight trucks and vehicles towing trailers or boats were legally only allowed to travel up to 90kph, and that won’t change, a spokesperson for the NZ Transport Agency Waka Kotahi said.

Kingham said if the minister wanted to increase productivity, this wasn’t the right move.

Transport export Professor Simon Kingham says time savings doesn’t necessarily equate to increased productivity. (File photo)

“That’s what makes the whole thing more stupid. It’s nonsense.

“It’s about time saving, it’s not about productivity at all, and that’s where the minister is getting confused.”

The 51 seconds was based on a smooth journey at 110kph for the whole 17.7km highway, which was unrealistic, he said.

“You’re just increasing the top speed. The ones who want to drive at 110kph will be stopping and starting and breaking more because they’re still going to hit the people going 80, 90 and 100kph.”

Shaving 51 seconds off a 30 minute commute wouldn’t increase productivity, Kingham said, but developing public transport options - like trains where people could work while on their commute - would, he added.

“A 45 minute train journey is deemed worse that a 30 minute car journey, even though you can be working on a 45 minute train journey.”

Consultation on the motorway’s speed increase closes on October 1.