So much for the road between Ōtaki and Levin being improved. In today’s Horowhenua Chronicle (23 August 2019) we see:
… as far as informing the community of the definitive [expressway] route by early August, enquiries with NZTA about its progress have generated a resounding: “No, because there is no money”.
… NZTA now also admits that there is no funding available at the moment for the promised safety measures on the existing SH1 between Ōtaki and Levin.
… Emma Speight, NZTA Director of Regional Relationships said … there is currently insufficient funding to invest in all the infrastructure that communities are asking for including new state highway projects.
… We do not currently have funding to progress this work further and we cannot say now if funding will be available in the next NLTP period (2021-24).
Source: Road to nowhere? NZTA admits it has no funding for Levin expressway – NZ Herald.
In the same issue of the Chronicle we learn too (Page 7):
Nick Leggett, chief executive of the New Zealand Road Transport Forum [says] … More than 90 per cent of New Zealand’s freight is transported by trucks, moving around the country all day, every day.
While the number of trucks on roads is predicted to remain steady in years to come, the volume of freight is set to increase dramatically, with a predicted growth of 58 per cent.
This growth brings even more pressure on roads.
Presumably if the number of trucks remains steady but the volume of freight increases dramatically then those trucks will be bigger or carrying bigger loads.

At least once the expressways are finished all those trucks should disappear.