An interview with Dr. Martin Löder, University of Bayreuth
Barrier-free planning and building for public transport and open spaces DIN 18040-3
By Alexander Nix, Landscape architect BDLA
The publication of DIN 18040-3 for public transport and open spaces in December 2014 completed the DIN 18040 series of standards.
DIN 18040-3 regulates a minimum standard. It thus offers the cadre for barrier-free planning in public transport and open spaces. It formulates protection targets and points out that these can be "fulfilled in ways other than those specified in the standard".  This standard opens up a vast area of creative leeway for planners. Barrier-free planning is more easily adapted to individual situations.
The new DIN 18040 series of standards introduces the two-senses principle. Accordingly, in future all information needed for the barrier-free use of transport and open spaces will be transmitted in such a way that at least two of the three senses, seeing, hearing and touch will be addressed.
This means that
- visual data must also be presented in a tactile or acoustic manner,
- tactile data must also be visual or acoustic,
- acoustic data must also be presented in a visual or tactile manner.
- must be designed with plenty of visual contrast for visually-impaired people,
- must not be overlain with notices of another kind (e.g. advertising, projecting advertising at floor level, lettering on the steps etc.),
- should be linked into an integrated and networked signage system and
- must be accessible for the visually impaired and wheelchair users if they are readable only from a short distance away (e.g. timetables)
- must be audible and comprehensible for people with hearing impairment; reverberation and the relationship of background noise to the desired signal are important influential factors (interval of at least 10 dB)
- should automatically adjust to changes in the level of background noise and
- should be introduced by a tone sequence; these tone sequences must be clearly distinguishable from warning signals
- must be suitable for and recognisable through every type of perception (fingers, hands, white cane, feet)
- must be distinguishable from their immediate environment e.g. by virtue of shape, material, hardness, surface roughness etc. and
- in written form, apart from being communicated in raised upper case letters should also be produced in the Braille alphabet for the blind, and at the same time they should not be replaced by tactile pictograms and special characters
Data in the case of cognitive impairment
- must be readily comprehensible and really noticeable
- if in written or spoken form must inform in "simple language"
- should be repeated as acoustic information (retentiveness)
- should contain pictorial or graphic symbols or photo-realistic displays instead of or in amplification of a written text
- should be linked into an integrated and networked signage system with elements in the same order, size, colour and lighting
Space requirements and play surfaces: The basic requirements for the size of the surfaces and space for mobility-impaired persons are predominantly equivalent to the dimensions specified in DIN 18024-1, which is still in force. For space requirements, manoeuvring areas and play surfaces, this standard specifies a surface area of 1.50 x 1.50 m. The narrowest permissible width for passageways at bottlenecks is at least 0.90 m. The only dimension reduced in the new standard is the minimum width for meeting areas, which is reduced to 1.80 m. This also becomes the required minimum width of walkways plus the safety margin of 50 cm specified in RAST06 for streets and 25 cm for the façades of buildings. All spaces and play areas must also be kept free of obstacles. Clearance for height must not be less than 2.25 m, which conflicts with DIN 18040-1+2 (2.20 m) and DIN 32984 (2.30 m).
The space between circulation cabinets is increased to 1.50 m. Entrances and exits from this barrier must be at least 0.90 m in width.
In derogation from this draft standard the required space for stationary motor traffic in the current discussion has once more been defined as 3.50 x 5.00 m for the side exit and 2.50 x 7.50 m for the rear exit.
Longitudinal and cross slope
The limit for the cross slope for paths has remained at a maximum of 2%.
This, however, shall apply also to access roads to properties and crossing points. Access roads to properties should then become accessible over inclined curbs. Crossing points can meet this requirement by lowering the path across its entire width. This will reduce the incessant, energy-sapping drifting of walking frames and wheelchairs. In level areas without any longitudinal gradient transverse gradients are permissible up to a maximum of 2.5%.
The guidelines for the maximum longitudinal slope of 6% for paths are the same as for the old standard; however, for short stretches of up to 1.00 m in length DIN 18040-3 now allows slopes of up to 12%.
The surface areas of paths are very precisely defined in the new standard. Thus for cobbled paths a serrated surface is recommended and for other pavements a non-reactive design with the smallest possible joint width is recommended.
The required slip resistance is defined as the SRT value of >55 or the R-value of at least 11 or 10 V4.
Crossing points: If the crossing of a road is in principle not excluded for pedestrians, in the future there must be barrier-free crossing points at least at all road junctions. Alternatively, these can be designed as divided crossing points in accordance with DIN 32984 with differentiated curb heights or as a universal crossing point with curb heights of 3 cm. The curb edges should be rounded to r = 20 mm.
Transport facilities accessible to the public: The dimensions and marking of movement areas in bus and railway stations is at least 2.50 m and thus complies with the old standard. However, the distance and height difference of the entrance to the vehicle and the edge of the platform have altered. Instead of the original 3 cm, 5 cm is now permitted. This can present an insuperable barrier to wheelchair users and is therefore not ideal.
In addition, in accordance with the two-senses principle (see above), warning notices, guidance and passenger information has been included.
The level pedestrian crossing points for railway lines are a new component of the standard. The design should, as a rule, be barrier-free in accordance with DIN 32984.
Ramps and flights of stairs: The specifications for ramps with a maximum slope of 6%, a maximum ramp length of 6.00 m, a minimum width of 1.20 m and with handrails and wheel deflectors are predominantly based in principle on the specifications in the already existing standards. An important innovation, however, is that flights of stairs leading downwards may be extended with ramps, namely at a distance of 10.00 m at the lower end of the ramp and at a distance of 3.00 m at the upper end.
The requirements for flights of stairs have also changed. Thus, on the one hand, turning staircases from a stairwell diameter of 2.00 m and step undercut of up to 2 cm with inclined risers are permitted, and on the other hand, markings are required on the edges of steps on all types of staircase, irrespective of the height of the step. Last-step indicators at the start and finish of a flight of stairs must no longer be highly contrasting, but must be designed as far as possible in the same colour scheme as the stairs. The very different specifications in DIN 18024-1 had led in the past to numerous accidents.
Green spaces and leisure facilities, open spaces: There is clear relaxation of the specifications for green spaces and leisure activities open to the public. The re-location of toilet facilities is no longer a mandatory requirement and it is necessary only to provide movement areas of 1.50 m x 1.50 m on byways within visual distance; this width, however, does not allow two wheel chair users to meet. The requirement for placing benches is only that they should be a "reasonable" distance apart. What is considered a "reasonable" distance is unfortunately left open for debate.
Numerous model projects, examples and experiments show that open spaces can and should be organised to give tangible experiences to people with sensory or motor disabilities. This new aspect is given considerable attention in DIN 18040-3. Together with the guidelines for producing a barrier-free guided route for the blind and visually impaired it is recommended that a plan taking tactile experience into account with strong visual contrasts is prepared for the respective open space. At bathing places the entry into the water for people with motor difficulties should be designed over flat steps with a handrail on both sides or a sloping surface with a firm underfloor. Angling sites must be barrier-free and accessible and it must be possible to use them without risk. The minimum area per angling site is specified as 1.50 m x 1.80 m. An upstand with a minimum height of 0.15 m on the sides where there is a danger of falling, can be provided as an alternative to a guardrail.
It is quite normal to be different
There is no standard norm for humanity. Nevertheless it is important to develop directives and standards together with those concerned, in order to achieve a consensus amongst the various interested groups with restricted mobility. Therefore this is taken into account in the DIN 18040 series of standards with the recently introduced two-senses principle, which recognises that there is loss of capacity in several of the senses with increasing age (e.g. visual impairment and hardness of hearing). In order to obtain a realistic idea of how barriers in open spaces affect people with loss of capacity, it makes sense for the open space planners to go beyond the requirements of the respective DIN standards and to put themselves in the situation of those affected. An excursion through town in a wheelchair, a stroll wearing simulation spectacles and carrying a white cane or exploring the district wearing an age simulation suit open up new perspectives and engender understanding for the problems faced by people with impaired mobility.
Ultimately a barrier-free world has benefits for everyone.
For 10% of the population it is indispensable, for 30-40% of the population it is necessary and it is convenient for everyone. Planning for accessibility for disabled persons is consequently also planning for people in general.
We are all different and therefore each one of us is unique. This paradigm shift is perhaps still a vision or a pipe dream. It will however make life livelier, more exciting, more colourful and above all, happier for all of us. However, this requires all of us, in particular those in the disciplines concerned with planning of open spaces, to think differently and to set off in a new direction towards the creative design of barrier-free spaces for living. The new DIN 18040-3 gives us plenty of room for manoeuvre for this purpose.
Photo: illustration from MenschWerk, Institut für humane Umfeldplanung