I heard recently that Auckland's yellow street lights are going to be replaced by white LED lights. Is this true? Do you know when it will happen, and why? Mark Stewart, Kingsland.
Auckland Transport owns more than 100,000 street lights, approximately one-third of the country's total lighting stock. Just over 44,000 of the current high-pressure sodium (golden yellow light) street lights will be replaced by energy-efficient light-emitting diodes (LED) luminaires.
The replacement programme will begin early next year, in the first phase of a five-year plan.
Auckland Transport estimates net savings of $32 million over the 20-year design-life of the LED luminaires.
AT has had a policy since 2012 that all new lights on pedestrian-dominated roads will be LED luminaires. Changing the old lights to LED luminaires will reduce the energy consumption by over 50 per cent.
Auckland Transport already has approximately 2000 energy-efficient LED luminaires in service.
At the same time the new luminaires are changed, a Tele-Management System (TMS) will be installed to manage and monitor the network.
Through better management of light levels, a further 15 to 20 per cent of energy savings can be achieved.
The TMS will provide enhanced customer service as any faults on the network will be reported daily.
AT already has LED luminaires around Eden Park which are controlled by a TMS system. This was established under an earlier project and has worked well by increasing light levels before and after events.
International experience has shown that white light is also a factor in crime prevention, delivers greater comfort and security and improves visibility and reaction times for drivers and pedestrians.
When I take my children to the local playground, I am always pleased to see the wood chips on the ground under swings and climbing frames. It seems to be pretty resilient and safe. However, I am puzzled by the blue colour on some of the chips. Has someone gone around painstakingly applying the paint to some of the chips (paint fairies?) or is there another explanation? Annie Brookfield, Mt Eden.
A much more prosaic and less magical answer, I'm afraid. The wood chips are supplied by a company called Reharvest, which recycles used timber into mulch and wood chips, for just such use as you describe.
Some of the timber comes from old pallets, which have had the company name painted on them, in blue.