a. Definitions
Barriers/fences, guardrails and bollards are ways of delineating an area. They may be required for safety or other reasons to restrict the movement of people or, more usually, of vehicles (Figures 7.5 and 7.6).
Figure 7.5: Vehicle defense bollards have been placed over the tactile paving at King's Cross station, London, photograph courtesy of Helen Allen.
b. Design issues Provision
Fences/barriers and bollards should be kept to a minimum, only being used where essential for safety reasons. When poorly designed or positioned, they can increase the distance that people have to walk, reduce the width of the footway and can cause injury to pedestrians or cyclists crushed against them.
Guarding is necessary to prevent people falling where there is a significant change in level, and to prevent people from inadvertently colliding with obstacles such as low soffits.
Bollards are usually used to prevent vehicles encroaching on pedestrian areas. They should not be used unless essential: other items of street furniture with a specific function, such as seating, cycle stands or planting, can be used as an alternative and are preferable.
Bollards should not be linked with chains or ropes or have horizontal arms: these are a hazard for blind and partially sighted people. Rise and fall bollards should have audible sounds when in operation.
Location
The positioning of barriers/fences and bollards should not obstruct or restrict pedestrian routes, or be a hazard in open areas.
Water
It is inappropriate to provide guarding around certain water edges, e.g. canals, rivers and lakes. However, in some urban settings a tactile warning surface could be used as an edging strip, and should be at least 800 mm wide around the water’s edge.
Dimensions
Barriers/fences and bollards must be sufficiently high so that they are not a trip hazard. Guardrails must be high enough to prevent people falling over them. All barriers/fences and guardrails should have a continuous upstand or rail close to ground level to provide cane users with a tapping rail.
Guardrails should be designed to prevent guide dogs from walking underneath the railings and should also ensure that children and wheelchair users can see, and be seen, through the railings.
Safety and anti-vandal design and construction
Barriers/fences and guardrails should not be climbable and should not have gaps wide enough for a child to squeeze through.
Visual identification
All barriers/fences, guardrails and bollards should visually contrast with their background, or have visually contrasting markings, so that they are not a hazard for blind and partially sighted people.
Lights integrated into bollards can make them more visible.
Figure 7.6: Mobile planters define the external seating area, Westfield Stratford City, London, photograph courtesy of Helen Allen.
c. Specific recommendations
Guarding should conform to Building Regulations 2010 Part K, BS 8300:2009 (amended 2010), BS 6180:1999 and Inclusive mobility (DfT 2002).
Table 7.1 Recommendations for guarding.
Category Issues Detailed considerations
Source if not BS 8300:2009
Guarding
Provision
Guarding is required to prevent people falling where there is a change of level other than stairs or a ramp of more than 380 mm. On the open sides of stairs and ramps, guarding is required where the drop is greater than 600 mm.
Guarding is also required to protect people from obstructions, such as open soffits underneath steps/stairs and ramps, that are less than 2,100 mm high.
Location
Guarding should be placed at the edge of a drop, stairs or ramp.
It is preferable that it is fixed to the vertical sides rather than the horizontal surfaces, ramp surface or treads, so that fixings do not gather dirt or trap rubbish, and do not obstruct cleaning.
Poles should be 500 mm minimum from the edge of the carriageway and at least 1,000 mm apart. Guarding should preferably be separate from handrails.
Guardrails and bollards should not intrude into the required width for pedestrian routes; see Section 4.1.
Dimensions
Where the drop on the open sides of ramps is more than 600 mm, there should be guarding to a height of 900 mm minimum from the pitch line; 1,100 mm is recommended. Landings with open sides should have guarding to a height of 1,100 mm.
Guarding to protect people from obstructions, such as low soffits underneath steps/stairs and ramps, should be at least 1,000 mm high and with low-level cane detection 100–150 mm high, or a continuous raised flower bed at least 900 mm high or a warning surface not intended to be walked on, such as cobbles, but this must not constitute a trip hazard.
Safety Guarding should not be climbable, for example have horizontal rails, and should have no gaps or openings greater than 100 mm.
Visual identification
Guarding should visually contrast with its surroundings. If it cannot be of a material that contrasts, then it should have contrasting markings on it.
Inclusive mobility