Lies, damned lies, and statistics about the Kāpiti Expressway


If Julie Anne Genter has any responsibility for the transport portfolio in the new Labour-led Government I hope she doesn't try and mislead people with statistics like she did back in May regarding the MacKays to Peka Peka Expressway.

You see, back in May I spotted an article claiming that the MacKays to Peka Peka Expressway (known locally as the Kāpiti Expressway) had slowed the commute into Wellington by 10 minutes. Something smelt fishy to me about that claim. At the time I'd been driving that commute at least a couple of times a week from Paraparaumu (other days I'd take the train) and that claim simply didn't equate with my anecdotal experience.

Sure, there was a slightly increased queue at MacKays crossing as traffic merged, and the queue started earlier in the morning, but overall my commute to and from town was quicker, largely because the perpetual merge northbound in the evenings at Raumati South, traffic lights and another merge at Paraparaumu, and the Otaihanga roundabout had all been bypassed.

Julie Anne Genter had sourced her information in written questions to then Transport Minister Simon Bridges. You can read them here and here. What's notable about her questions is that she only asked about Paekakariki, which is south of the Kāpiti Expressway, so was never going to directly benefit from its construction. Everyone on the Kāpiti Coast knows this. Paekakariki has terrible access on and off the current State Highway 1, it's a notoriously dangerous intersection, and the more steady flow of cars caused by no traffic lights breaking up the flow in Waikanae and Paraparaumu would make things more difficult for that community.

However everyone on the Coast also knows that Transmission Gully, when it's finished, will completely remove traffic issues for Paekakariki, as State Highway 1 will turn southbound north of the town, restoring its peace and quiet, and enabling locals to more easily commute.

Julie Anne Genter had gone for as misleading a measure of the impact of the Kāpiti Expressway as she could. For a party that's tried to pride itself on its honesty, and integrity, it was hugely disappointing.

So I sent an OIA into NZTA to find out what the actual data said about the communities who did benefit from the Kāpiti Expressway. And while it's only indicative at this stage, as the TomTom and BlipTrack data aren't completely comparable, it still suggests quite a different story to what Julie Anne Genter claimed. Data from 24 February to 28 April showed net savings across the board, ranging from just a minute saved in Paraparaumu, to a total saving of 15 minutes if you were driving in from Ōtaki.

Source: TomTom and BlipTrack data 24 February 2017 to 28 April 2017 versus 2016 average commute times, courtesy of NZTA.

Source: TomTom and BlipTrack data 24 February 2017 to 28 April 2017 versus 2016 average commute times, courtesy of NZTA.

So while there had been a 10 minute increase in the morning from Paekakariki, it was largely offset by gains from the Kāpiti Expressway north of Paekakariki. Only from Paraparaumu (and presumably south of that in Raumati and Raumati South) were morning commute times slightly increased. Where the big benefit came though was in the evening rush hour, where bypassing the choke points at Raumati South, Paraparaumu, and Otaihanga, delivered big savings for commuters.

And that's the average saving too. I imagine that if you looked at data on Fridays in particular, especially in the evening, it would be much more significant, especially as those commuters on a Friday often include people from Wellington who are heading north for the weekend.

As of this morning I've sent another OIA to NZTA to hopefully get the August and September figures using the TomTom data so that it can be directly compared to TomTom's August and September data from previous years too, and I can see if the savings hold up comparing exactly like for like data. Likewise I'll hopefully check back in May next year to see how the commuter chaos season played out on the road too.

It's hugely disappointing to see someone like Julie Anne Genter pull off a stunt like this. She's generally respected for her work in the transport space, and is from a party that prides itself on its honesty and integrity.

Yet in this case she appears to have misled the Kāpiti and Wellington communities by misusing statistical data to claim the Kāpiti Expressway was increasing commuter times when it seems that for the most part, those communities who were meant to benefit from the Kāpiti Expressway are getting those benefits.

Let's hope that if she is involved with the transport portfolio in the new government that we don't see a repeat of this.

The Kāpiti Coast, at least up to Waikanae, has pretty decent public transport into Wellington. Yet our roading network had been largely ignored for nearly two decades bar MacKays Crossing and the Otaihanga roundabout.

With ongoing rapid population growth, about a third of the district commuting into Wellington daily, and recent natural disasters highlighting the vulnerability of existing rail and road links between Kāpiti and Wellington, the reality is that projects like Transmission Gully, the Kāpiti Expressway, the Peka Peka to Ōtaki Expressway, securing funding for the Capital Connection rail link between Palmerston North and Wellington, and the possible extension of the rail commuter network to Ōtaki, are all needed to help cater for that growth and create the resilience needed for the lower North Island's integrated transport network