Agree. Aotea (Porirua) to Waikanae now sends me via Waitangirua interchange. Coastal route 31 min-37.9K, TG 30 min-37.9K.
BUT, the time doesn't take into account the snarlups I have been in on the coastal route! SH1 for me everytime.
Edit to add. The coastal route is devoid of cars and trucks now. GREAT relief to the coastal villages.