Photometric requirements
Urban streets usually have to be lit according to the requirements of Class M2 or M3 of CIE publication No. 115-2010, depending on their importance and the traffic conditions.
| Class M2 |
Lave = 1.5 cd/m² |
Uo ³ 0.4 |
Ul ³ 0.7 |
TI £ 10% |
SR ³ 0.5 |
| Class M3 |
Lave = 1.00 cd/m² |
Uo ³ 0.4 |
Ul ³ 0.6 |
TI £ 15% |
SR ³ 0.5 |
Light sources
Urban streets should be lit using white light, in order to provide a good colour rendering and a comfortable luminous ambiance.
Therefore, metal halide lamps (compact ceramic burner lamps and CosmoWhite lamps) or warm white LEDs are recommended.
Luminaires
The luminaires chosen to light urban streets should have a high level of tightness (at least IP 66), in order to maintain initial performances for as long as possible throughout the lifetime of the installation.
When the luminaires or lanterns are installed at a very low mounting height (up to 5m), consideration must be given to vandal resistance by using strong materials for the construction of the lanterns, like aluminium for the body and glass or polycarbonate for the protector bowl.
These luminaires will preferably comply with the Green Light Label as defined by Schréder.
Installation layout
The use of aesthetically well designed lighting material is preferred by day to contribute to the harmony of the commercial urban environment. For the same reason, the mounting height of the luminaire should be kept relatively low (at least lower than adjacent buildings). Pole heights of 8m or 10m are considered as a maximum.
In an urban environment, a staggered installation may also be used, in order to balance the light in a better way on both sides of the street.
The lighting installation shall be energy efficient, with a SLEEC-L value (Street Lighting Energy Efficiency Criterion Luminance based) being at a maximum equal to 0.8W/m²/cd/m².
An accurate knowledge of the light reflection characteristics of the pavement is of primary importance to meet the above efficiency criterion. These characteristics can be measured by our exclusive system known as Memphis. |
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Examples of lighting installations for urban streets
Installation at a low height (4.5m) of CITEA Midi luminaires in a single sided arrangement.
A 70W metal halide lamp with ceramic burner has been used to provide luminance results in accordance with the requirements of road class M3. |
Installation of HESTIA luminaires in a single sided layout. Mounting height is 8m here, with the luminaire in a horizontal position.
The Hestia luminaires are equipped with 90W CosmoWhite lamps and provide an average luminance level of 1.5cd/m², complying with class M2 specifications. |
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