How to light Residential Streets
Residential streets usually have to be lit according to criteria for P classes, defined for pedestrian and low speed traffic areas. For this kind of area, the luminance concept is not applied, as users do not only include drivers looking straight ahead, but also people viewing the surroundings. Cyclists and pedestrians are also main users of these areas.
The quality criteria applied for lighting of residential streets are consequently illuminance based.
If facial recognition is necessary for pedestrians, additional requirements like minimum vertical illuminance (Ev,min) and minimum semi-cylindrical illuminance (Esc,min) have to be fulfilled as well.
The values of the lighting criteria to respect for the different P classes are as follows, depending on local conditions of traffic and environment configuration.
The selection of the right class to be used is described in the CIE 115-2010 publication.
|Class P1||Eave = 15 lux||Emin = 3 lux||Ev,min = 5 lux||Esc,min = 3 lux|
|Class P2||Eave = 10 lux||Emin = 2 lux||Ev,min = 3 lux||Esc,min = 2 lux|
|Class P3||Eave = 7.5 lux||Emin = 1.5 lux||Ev,min = 2.5 lux||Esc,min = 1.5 lux|
|Class P4||Eave = 5 lux||Emin = 1 lux||Ev,min = 1.5 lux||Esc,min = 1 lux|
|Class P5||Eave = 3 lux||Emin = 0.6 lux||Ev,min = 1 lux||Esc,min = 0.6 lux|
|Class P6||Eave = 2 lux||Emin = 0.4 lux||Ev,min = 0.6 lux||Esc,min = 0.4 lux|
Residential streets are quite often lit with high-pressure sodium lamps, meaning a relatively low colour rendering index. However, recent studies on mesopic vision have lead to recommendations to use white light for areas where the peripheral vision of users is of important contribution.
Therefore, metal halide lamps (compact ceramic burner lamps and CosmoWhite lamps) or warm white LEDs are recommended.
The luminaires chosen to light residential streets should have a high level of tightness (at least IP 66), in order to maintain initial performances for as long as possible during 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 vandalism 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.
The use of aesthetically well designed lighting material is preferred by day to contribute to the harmony of the residential 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 6m to 8m are considered as a maximum.
Staggered installations may also be used frequently, 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-E value (Street Lighting Energy Efficiency Criterion Illuminance based) being at a maximum equal to 0.07W/lux/m².
The following drawing shows a typical installation for a residential street.
Examples of lighting installations for residential streets
Installation on 5m high straight poles of EVOLO 2 luminaires in staggered rows.
The 60W CosmoWhite lamp has been used to provide with white light the illuminance results for a class P1 of residential streets.
Installation of K-LUX luminaires in a single sided arrangement. The mounting height is 4.5m. The luminaires are equipped with 45W CosmoWhite lamps and provide an average illuminance level of over 5 lux, complying with the requirements of class P4 specifications.