Roundabouts form typical conflict zones in road lighting in accordance with DIN EN 13 201. The roundabout must be illuminated if the roads leading to it are also illuminated. A degree of illuminance of 20 lx on the carriageway in the roundabout, without pedestrian crossings, represents good illumination. On driveways, the illumination level should be gradually increased from 5 lx to 20 lx based on the permitted speed. The transition should be gentle in order to keep the contrast as low as possible and to allow the human eye to adapt quickly. A slight change in light colour compared to the road lighting also increases the level of attention.
The illumination of pedestrian crossings at a roundabout is subject to the standard DIN 67 523. Here it is important that pedestrians are easily recognisable on the crossing and in the adjacent waiting zones. For this reason, an average vertical illuminance of Ēv = 30 lx is used. Here, Evmin is 4 lx. Pedestrian crossings and waiting areas must be illuminated from the direction of approach. 100 m before and after the pedestrian crossing, the luminance must be 0.3 cd/m2. To achieve this we equip the street luminaires 99 595 with special optical modules. If illumination class M 2 (1.5 cd/m2 or 20 lx) is achieved over a distance of at least 50 m before and after the pedestrian crossing on the street, additional illumination can be dispensed with.