Rotating grille
A circulating grid or a circulation check , according to DIN 18040-3 circulation barrier (s) (commonly known pedestrian railings ) is an arrangement of bars which act at the end of a path or on a path as a barrier. In order to follow the path, the grids must be circumnavigated or bypassed in the form of a serpentine or Z-shape. There are different arrangements, for example as a passage in a grid, in front of which a second grid stands as a barrier, or as two intermeshing U-shaped parts.
purpose
Circulating grilles usually serve two different purposes. On the one hand, they slow down pedestrians and cyclists, for example at the exits of schools and kindergartens, so that children do not storm onto the road , or on cycle paths that cross main roads. However, they may "only be used at crossing points with poor visibility or heavy vehicle traffic (collection roads and main roads)". On the other hand, rotating grilles are used at level crossings for pedestrians and cyclists.
Circumferential barriers can be combined with a light signal or St. Andrew's cross . In contrast to the barrier-free level crossing, there is no scheduled waiting time, the passers-by are only called to be cautious by slowing down and turning their gaze around. The straight, sometimes thoughtless, fast crossing of the danger point is to be prevented, attention is drawn to the danger without actually hindering the pedestrian. In contrast to the overpass or underpass, it is a level crossing at the same height. Sound signals are common at some level crossings.
Particularly at crossings with double-track tram lines, circulation barriers are arranged so that a pedestrian looks against the normal direction of travel of the closer track before leaving the barrier and then has to cross the tracks slightly diagonally, looking against the other track.
criticism
In practice, rotating grilles always have undesirable side effects. They are often not passable or passable only with difficulty by wheelchair users , strollers, bicycles with trailers , cargo bikes and tandems .
Even with a normal bike, basket or wide handlebars, the traverse is often difficult, requires or forces dismounting, and even then on foot, pushing next to the bike, is cumbersome and sometimes difficult due to the available width and curve radii.
At poorly constructed circular barriers that are frequently used, there is occasionally evasive traffic, creating a beaten path or using the road next to it.
Concentrating on cycling through a circular barrier can mean that cyclists do not pay sufficient attention to a street or railway line to be crossed.
Cyclists or people with long items of luggage cannot evacuate the danger area within the planned time due to the tight outer curve radius, even when leaving the danger area . Both the recommendations for bicycle traffic facilities (ERA, under 11.1.10) and the recommendations for pedestrian traffic facilities (EFA, under 4.1.2 for wheelchair users) provide for a minimum distance of 3 m between the barrier and the road or track system to be crossed, but how other of the requirements are not always complied with. In addition, the distance is not sufficient for longer bicycles and bicycles with trailers and partially prevents pedestrians from being able to see the railway line from the circular barrier. ERA and EFA also outline the circular barriers only for the case of separate paths that meet the traffic route to be crossed. The recommendations for public transport systems (EAÖ, under 7.1), which outline the circulation barriers between road and rail, still do not provide for such minimum distances to road or rail in the latest version from 2013. However, the text requires: "The EFA, the RiLSA and the H BVA must be observed." (H BVA = instructions for barrier-free traffic facilities).
Badly marked barriers can be overlooked by strangers when driving at night or driving too fast with the following collision.
Related arrangements
The extensive arrangements of barriers made of handrails or safety belts that channel the queues at check-in counters, large fixed rides, etc., belong in the broadest sense to the circulating grilles as well as the breakwaters in large event rooms.
Cattle bars and stiles are sometimes similar, constructed as a pass-through, as a rigid or movable kissing gate . Hikers can pass here while dairy cattle remain in the area, on the meadow or pasture.
In large laboratories and in film production, similar circuits sometimes serve or served as access to the dark or darkroom area , light is blocked out through this U-shaped passage, a light trap painted in black.
In public or heavily frequented buildings in particular, doorless passages can be structurally calmed and noise-insulated through appropriate design. Ventilation systems are sometimes designed in the same way.
In the military sector, angled entrances to casemates or bunkers were used to trap projectiles or fragments. The space in front of city or castle gates or the space between the inner and outer gates of walls or ramparts is often designed as a circulation for defense. Similar design features and reasons can sometimes be found in the ramparts, moats and castle walls divided by moats or towers, and in the trenches of the First World War, which were divided into short sections .
Minimum widths
Insofar as rotating grilles have to be used for reasons of traffic safety, DIN 18040-3, the recommendations for pedestrian traffic systems and the recommendations for cycle traffic systems provide for minimum widths so that the barrier can be passed. In particular, "it should be possible to drive comfortably and safely with wheelchairs [...] or a bicycle trailer without maneuvering". The minimum distance between the rotating grilles must be at least 1.50 meters, the grilles must not overlap. The minimum widths of the entrances and exits are defined differently in ERA or EFA and DIN 18040-3. In ERA and EFA, the minimum widths given in the adjacent table are given depending on the width of the path. In DIN 18040-3, a width of 90 centimeters is entered as a minimum in one illustration. However, the required width of the entrances and exits results in connection with the minimum size of a movement area of 150 x 150 cm that must also be met for the necessary change of direction in the circulation barrier.
Both ERA 2010 and EFA 2002 stipulate a minimum distance of 3.0 m from the traffic route to be crossed, so that, according to EFA, wheelchair users can “concentrate fully on the crossing process [...] after passing the barrier” or, according to ERA, avoid “cyclists only come to a stop on the traffic route to be crossed. "
See also
Web links
- Instructions for the safe installation of circulating barriers (nudge bars) and posts , ADFC Bergstrasse
- Circulation barriers and obstacles on cycle paths , working aid from the ADFC NRW (PDF, 108 KB)
Individual evidence
- ↑ a b DIN 18040-3 - Barrier-free building - Planning principles - Part 3: Public traffic and open space
- ↑ EFA - Recommendations for pedestrian traffic systems . FGSV-Verlag, Cologne, 2002. Chap. 4.1.2 Circulating barriers