High-impact freeway lighting

Lighting for freeways is an essential part of roadway infrastructures, but is often taken for granted. But compare driving at night on an unlit country highway to a well-lit freeway and the value of street lighting becomes very apparent.

The Department of Main Roads in Western Australia is very conscious of the need for adequate lighting on its roads and contracted lighting designer company Maunsell to design a suitable lighting system for the seventh and final stage of the Roe Highway project, a major freeway running through the southern suburbs of Perth, as well as make a bold statement with the lighting at the on/off-ramps to and from intersecting Kwinana Freeway.

The project was developed, designed and built by the Roe7 Alliance, made up of Main Roads Western Australia as the owner, Clough as the builder and Maunsell as the lighting designer.

A highlight of the artist-designed exterior lightwork is a row of seven 'entry statement' poles installed on the ramps to and from Kwinana Freeway. These designer poles are public artworks that also act as a functional part of the freeway's lighting scheme. The entry statement poles - depicting the number '7', were painted in a gold colour inspired by the native WA Christmas Tree.

The entry statement lights incorporate Thorn Alpha 2000 luminaires, fitted with 250 W HPS 33,000 lumen optics. Maunsell's lighting designer for the project, Ivan Semmler, who chose the Thorn luminaires said: "The Alpha 2000 was selected because of its excellent photometrics, as well as the ability to adjust its lamp holder to suit different situations such as varying road widths, while still giving maximum spacings."

Overall, there were more than 600 Alpha 2000 luminaires used in all stages of the Roe Highway project, as well as over 150 Thorn Civic 1 vandal proof luminaires with 100 W HPS lamps for the shared path lighting along with a number of Thorn Panther luminaires with 38 W 2D lamps for pedestrian and cycle underpasses. All luminaires used on the project were energy-efficient high-pressure sodium lamps.

The primary design criteria for the lighting on the project were the Australian standard AS/NZS 1158.1 Cat V3 lighting levels and Main Roads Western Australia's requirement for vandal proof fittings for the pathways and underpasses.

Thorn Lighting provided considerable assistance to both the lighting designers and builders throughout the entire design and subsequent delivery process. They also assisted greatly in the selection and method of modification of the Alpha 2000 luminaires for the seven entry statement poles.