Those who drive down the ‘Ewy’ from Waikanae to Paraparaumu have probably noticed an approximately 1 km rough section beginning about where the sign is in the pic and lasting to about where the off-ramp to Kapiti Road is.

In our own car it’s noticeable, but driving in another car with poorer suspension on Saturday night, it was quite pronounced.

There is this article from July on the stuff website about water seeping through the membrane seal, which is meant to act as a waterproofing layer below the asphalt.  The same thing may explain why sand/lime seems to be leaching through the asphalt.

But the roughness indicates a bigger problem than just that. It may be a combination of:

• Inadequate substrate
• The nature of the sandhills or peat base
• Truck weights being too much for the strength of the road

We mentioned in a post earlier in the year that the government had increased maximum truck weights from 44 tonnes to 46 tonnes (a weight 10 tonnes more than that allowed on Interstates in the US).  With vehicle weights the deterioration factor increases not linearly, but exponentially.

The NZTA is going to have to sort this problem out before it can increase the speed limit to 110 km/h as the government recently announced is intended.