AS/NZS1158 STANDARDS AND THE M30 IN NEW ZEALAND
For over 30 years, AS/NZS1158 has, in various forms, prescribed the standard of road lighting design in Australia and New Zealand. For most of that time the standard has worked very well and has enabled councils and road authorities to design consistent road lighting schemes and to ensure satisfactory illumination of public motorways.
Now with the advent of LED street lighting there is a push to revise the way street lights are assessed and in New Zealand we are seeing the introduction of the 'M30 Specification and Guidelines for Road Lighting Design' which supplements, rather than replaces, the AS/NZS1158 series of standards. So why add an additional set of requirements to the mix?
LED Street Lighting
LED technology has changed up the game because it has a completely different light distribution when compared with traditional street lighting. Where traditional street lighting used a bulb or tubes to generate light which would spread in all directions, a single LED projects light in only one direction. It is the configuration of individual LEDs and the lens which covers them that which dictates the direction or light, and provides a lot more flexibility to the manufacturers than earlier street lighting.
This additional flexibility is great in that it allows much more granular control of different aspects of a luminaire's light, but it also created a great deal of ambiguity since the standards weren't written with it in mind.
As the standard was written, it was intended to give street lighting designers guidance on how to layout their luminaires such that a roads could be illuminated to a particular level. The two main categories were P and V which respectively stood for streets where lighting was primarily to create a safe pedestrian environments and for roads where lighting was primarily for the safety of drivers.
With a traditional luminaires, light dispersed in a more or less even way so the key criteria for a street lighting designer in terms of light selection was the power and efficiency of the bulb or tube. If a luminaire was casting excessive glare in any direction, the light could simply be blocked. LED lighting on the other hand was much more variable and the old rules of simply checking efficiency compared with pole spacing no longer applied. New benefits such as reduced waste light off the sides of the road and 0% upward waste light came to matter more. With the ability to project light further issues like glare have also started to become an issue.
Developed by Connetics and Opus together, the M30 provides a solid foundation for establishing minimum performance standards for luminaires. Unlike the AS/NZS1158 standards that provide a framework of comparison between luminaires, the M30 sets minimum performance levels against the standards across a long list of variables. In a small country, such as New Zealand, this is extremely beneficial. It sets a benchmark that can be used to standardise lighting performance across the nation and give manufactures clear and measurable performance objectives to meet.
Many of the basic performance attributes of the M30 are based around achieving a minimum of 90% of the top performing luminaire's results. This mentality pushes manufacturers to constantly innovate to improve while also being flexible enough to constantly adapt to new technologies. Under the old system where manufacturers could only design products with the AS/NZS1158 standards in mind, it was the equivalent of giving LED lighting manufacturers a ruler, but not telling them the desired size. With every council able to interpret their lighting requirements differently, it was impossible to make anything but the most generic luminaires for New Zealand. Now with the M30 available, manufacturers have clear performance objectives and can develop interesting, targeted products to better meet the needs of the local market on a viable scale.
After years of confusion in the New Zealand LED street lighting market, the combination of the M30 Specification and Guidelines for Road Lighting Design and the AS/NZS1158 standards are helping pave the way to a brighter, but not glary, tomorrow.