Lighting of traffic zones such as corridors, staircases and other traffic areas must be examined in connection with the lighting of adjoining rooms. Great differences in lighting tend to pose a safety risk due to varying levels of adaptation. This applies for artificially lit rooms bordering on traffic zones as well as for areas leading outside. This means there must be a distinction between day and night time and the corresponding lighting levels. Adjacent areas should feature luminance differences of no more than 1:10, otherwise transition zones should be created to accomodate a gradual change. For that purpose, the average (adaptation) luminance as a product of average illuminance on the traffic area and the reflectance of said are must be determined. Graphics for converting luminance into illuminance and vice versa can be found in figure.
For rooms with very high illuminance, e.g. electronics workshops with 1.500 lx, transition areas into corridors must be created to avoid adaptation errors. Often, such transition areas can only be located within corridors due to spatial limitations, which means that parts of the corridor must be illuminated at elevated brightness. For that purpose, the values according to table (item 5.2, 150 lx) applying to highbay racking must be used at minimum. Traffic areas and driveways with outdoor section e.g. connecting storage and manufacturing halls should be illuminated outdoors as well as indoors to ensure traffic safety – additionally, requirements according to EN 12464-2 (see also chapter 1.2.1 "Rules and standards") for outdoor workstation lighting must be complied with.
According to EN 12464-1 the entire traffic route, meaning the horizontal plane of the traffic route on the floor or at a maximum of 0,2 m above the floor, must be used as the reference surface in terms of uniformity Emin/Ē ≥ 0,40. For very wide traffic routes a marginal strip (e.g. with a width of 0,5 m) can be subtracted if it is not used for traffic circulation and hence does not need to be considered as "visual task area" (see also chapter 1.2.4).
Traffic routes with vehicles pose a higher safety risk for pedestrians due to vehicle collision hazards. Therefore, EN 12464-1 stipulates an elevated lighting level for such corridors.
At hall entrances, the adjustment of the lighting level of neighbouring traffic areas is particularly important. Consideration must also made for day-time and night-time operation.
For day-time operation, the indoor transition area must be illuminated with 2 x Ēm (values for Ēm see table), and at a minimum of 400 lx. For night-time operation, the transition area is outside the hall entrance and must be illuminated with 0,5 · Ēm to 0,2 Ēm. In both cases Ēm is the illuminance of the indoor area, which is not always necessarily a traffic area but can also be a working area with a higher visual task.
Example: The indoor area of an assembly hall for medium-fine assembly work is illuminated at 300 lx and features an exit (a hall exit) towards the outside. During the day, the area close to the hall exit should be illuminated at 600 lx. At night, 60 to 150 lx in the outdoor area of the hall exit are sufficient to provide traffic safety.
In work places accessible to the public such as banks and insurance companies, retail spaces, restaurants, theatres, concert halls, cinemas, trade fair and exhibition halls, museums and libraries, higher illuminance levels than specified in table should be provided for safety reasons in addition to considering visitors unfamiliar with the area, senior residents and persons with mobility issues, but also for promotional reasons.
In training facilities such as schools, adult education centres, nursery schools and rooms in healthcare facilities, higher illuminance levels provide extra safety and cleanliness on traffic routes (see chapter 1.4.10 "Lighting of training facilities").
Corridors in healthcare facilities are discussed separately in chapter "Lighting of rooms in the healthcare sector" (see also chapter 1.4.6) due to their particular conditions.
Driveways with human-vehicle collision hazards, e.g. involving forklifts, require a higher level of illuminance than traffic areas only used by pedestrians.