Tony McCartney, AT Group Manager Assets and Maintenance, explains summertime road maintenance in Auckland:
This time of year is peak time for maintenance on our road network.
The weather is better and there is less traffic, meaning we can work quicker, meaning jobs cost less to complete.
Our region has around 7500km of roads, so even working quickly there is a lot to do.
I often get asked why some roads are chip sealed and others are asphalt. Auckland Transport’s road resurfacing guidelines require that chip seal surfacing is used for resealing on low volume local roads.
Asphalt is normally only used on roads where the traffic volume exceeds 10,000 vehicles per day or in high-stress areas like busy intersections.
To keep up with the changing traffic volume we regularly use traffic counters -those small rubber pipes you sometimes driver over.
Not only do these tell us the volume they also inform us of the type of vehicle and the pattern of traffic. All this data is then used to make sure we are keeping up with the right maintenance and using the best type of surfacing.
I also get asked about loose chip after a road has been chipped. It does take a little while to get the chip fully bedded in but we want to get the road open again as soon as possible so this is why some chip will inevitably be transferred to tyres once we re-open the road.
Because we have such a large road network, we need to ensure our budgets stretch as far as possible. Chip seal costs $7 per square metre, half of which is paid for by the NZ Transport Agency and half by Auckland Transport. Asphalt costs around $30 per square metre.
AT’s urban chip seal budget is this year is around $17 million. If we only used asphalt, that budget would increase to around $70 million per year.
We also carry out routine maintenance on a wide range of assets including kerb and channel, catchpits, signs, footpaths, road marking and lighting.