Obstacles too close to the edge of a path can pose a significant hazard for path users.
At least one metre of clear space must be left each side of a path so that people do not run into obstacles or each other.
The minimum safe vertical clearance for a bike rider is 2.5m.
What’s the problem?
Obstacles too close to the edge of paths cause a hindrance and hazard to bike riders. There is a history of serious crashes caused by such objects and judges have found councils liable for damages where they have allowed hazards to be installed or to remain next to a shared path. Fences and barriers are a particular problem.
What are the risks?
The major risks from objects too close to the edge of a path are:
crashes of single riders if they hit obstacles or “snag” the handlebars or pedals;
collisions or close calls between bicycle riders and others due to them having to travel closer to each other on the remaining usable path width;
crashes or near misses from people not being able to see each other, or hazards, on the path;
crashes between path users and people/animals stepping unseen onto the path from behind a screen;
a perceived (or real) risk to personal safety, especially at night, as trees and shrubs can provide hiding places for would-be attackers.
What is the solution?
Leave at least 1m clearance each side of the path as a “shoulder” or verge where people can ride off or stop if needed without crashing.
Paths should be designed using an “operating design envelope” which allows for the safe use of the path with included minimal lateral clearances to obstacles. The "operating design envelope" includes the actual path width plus 1m of clear space each side. Objects can then be placed an appropriate distance outside this envelope. For a 3m wide this equates to a 5m wide envelope. The clear space each side of the path should be a path shoulder that is rideable but not necessarily as smooth or solid as the path itself (eg grass or compacted gravel).
Larger clearances are needed for some obstacles such as trees whose branches can block views or whose future growth will impede the path. Entrances to buildings should also be set back further from the path.
Of particular concern are obstacles which can snag the handlebars or pedals of a bike or which can injure someone hitting or falling onto them. Common snag hazards include vertical bars or elements of fencing alongside paths, particularly the end elements of fences and barriers. “Softer” objects can also pose a hazard as tree branches and vines can snag handlebars or pedals.
If objects alongside the path are unavoidable, for instance when a path travels alongside a building, or alongside a fence barrier to a drop off, then they should present a “smooth” surface to the path users and avoid elements that would snag the bike or person riding it. Objects at head, handlebar and pedal height are particularly hazardous. The Austroads Guide to Road Design (Part 6A) refer to a minimum lateral clearance of 0.5m where obstacles with “smooth features” “align parallel to the path”. This can be dropped to 0.3m only in exceptional circumstances ("provided the design and end treatments are appropriate, or where extenuating circumstances exist").
Sometimes paths are retrofitted into existing spaces, for instance along railway lines, and only minimal space is available. In these cases where there is little clearance either side of the path, measures need to be taken to make the path as safe as possible. This means maximizing sight lines and path width and removing or modifying remaining obstacles so they are clearly visible and unlikely to cause a crash. If modifying walls or buildings to create smooth surfaces, keep the path as wide as possible. Adding rails can sometimes reduce the path width by up to 40cm which negates the safety effects by forcing riders closer together.
Where the path curves, larger clearance to objects alongside the path are needed to maintain sight lines so people on the path can see potential hazards and each other. Path design and maintenance of path side vegetation should allow path users to see 30m of the path ahead. This allows them to see other path users and slow down (or stop) if necessary.
Obstacles too close to the edge of the path also can reduce perceived personal safety by providing places where potential assailants can hide and await potential victims. This is especially true of unlit paths in quieter areas such as alongside creeks or railway lines.
What do the guidelines say?
The guidelines refer to 1.0m recommended, and 0.5m absolute minimum lateral clearances between the bicycle operating envelope and objects beside the path. A less clearance should only be used where safe and where unavoidable.
p72, Section 7.7.1 – Clearances: “It is important for safe operation that adequate clearance is provided between bicycle operating spaces for cyclists travelling in opposite directions and between the cyclist operating spaces and potential hazards beside paths (e.g. fixed objects, vertical drops, steep batters).
The following guidelines should be applied for clearances between the cyclist operating spaces and potential hazards beside paths:
Where both the areas beside the path and the path alignment are both relatively flat a lateral clearance of at least 1.0m (0.5m absolute minimum) should be provided between the edge of any path and any obstacle, which if struck may result in cyclists losing control or being injured. However, on high-speed paths it is most desirable to have a clearance considerably greater than 1.0m;
Where it is considered that a hazard beside the path has attributes that could cause serious injury to cyclists (e.g. sharp surfaces such as the rear side of the posts and rails or steel W-beam road safety barrier), designers should assess the risk of cyclists losing control of the particular section of path, and consider either increasing the lateral clearance or shielding cyclists from the hazard. Depending on the situation a rub rail behind the posts or a cyclist fence near the edge of the path could be provided;
Where a vertical drop or a steep batter exists or must be provided adjacent to the path the guidance in Section 7.7.2 should be applied.
Obstacles beside paths include bushes, culvert end walls, trees and large rocks used in landscaping. Provided the design and end treatments are appropriate, or where extenuating circumstances exist, a lesser clearance may be acceptable for fences and other obstacles that have smooth features and are aligned parallel to the path (0.3m absolute minimum).
These horizontal clearances are partially illustrated in Appendix A.
The minimum vertical clearance required by cyclists is 2.5m, measured above the riding surface (also shown in Appendix A) (sic – actually in Figure 4.7, section 4.2.2). This applies to tree branches, underpasses, doorways, sign structures and any other overhead structure."
Figure 5.1 (below) gives examples of clearances from a shared path to obstacles within a road reserve.
What does Bicycle Network Victoria say about the guidelines?
The guidelines do not place enough emphasis on designing paths with an “operating design envelope” that incorporates rideable shoulders on each side that allow riders to safely “run off” the path if needed.
Though the guidelines refer to operation envelopes for bike riders and the need for space each side of riders, the emphasis is on provision of lateral clearances to other path users and objects immediately alongside the path.
The new guidelines refer to a recommended 1.0m lateral clearance with 0.5m “absolute minimum” which is an improvement on the old 0.3 m absolute minimum that tended to become the default in tight situations. The lesser 0.3m clearance is only allowable where obstacle are "smooth features and are aligned parallel to the path" where "extenuating circumstances exist."
The result should be an improvement in the design of paths which, at times, have been designed allowing only for the minimum path width and minimum clearances to obstacles.
Any examples, good and bad?
St Georges Rd path, Northcote (at about Melways 30, D6) Pathside vegetation has overgrown the path making it hazardous for path users. The right and centre photos show the vegetation growing over the path. At right, a bike rider has to ride in the centre of the path to avoid palm branches. At centre, bushes grown over the edge of the path reducing its usable width. The palm to the left blocks views of any traffic at the intersection. The photo at left how the path newly built. Notice the bushes alongside the path have been set back almost 0.5m. Newly planted they do not block the path but have quickly grown across the path. They should have been set back at least 1.5m to allow for future growth.
Examples of fences that are hazardous to bike riders. At left the Main Yarra Trail at Mary St (ramp on right, Melways 2M, B2) the fence has been erected right up to the edge of the path on the path corner and leaned over the path. Not only does this reduce the usable path width but the vertical pole of the fence could snag on bicycle pedals. The fence could have been set back from the path. In centre, the Moonee Ponds Creek path at Dean St (Melways 29,B8) the top part of the fence intrudes on the path and can catch handlebars. Also, anyone crashing into the end piece of the fence is likely to be injured. At right the Bay Trail in Hobsons Bay has wooden bollards along the edge pose a hazard to path users. Not only have they been place on the edge of the path but have since loosened in the ground and lean over the path itself. They are likely to catch on bike pedal and are likely to injure anyone falling on them.
The fencing along the Bay Trail at Middle Brighton Baths is much better. The fence is set back from the edge of the trail and curves so that the top rail is smooth and at handlebar height. There is little chance of snagging pedals or handlebars. The full width of the path is still available on this boardwalk section.
Upfield Path, Brunswick. Before and after replacement of fence. The old wooden fence was built on the edge of the path. The new steel fence was set back about 30cm from the edge and reduces the crash risk on the path. The verge of the path beneath the fence needs to be reinstated to the level of the path to remove the lip that could still cause crashes from wheels being deflected. The wall at left also needs a smooth surface as the vertical pillars can catch handlebars and cause a crash. A wooden board 30cm high at 1.0 to 1.3m height would be one solution.
Often signs or temporary structure are placed too close to the edge of paths. Here the portable traffic hazard sign is over the path and the sign itself is at head height.
The following are pictures of the figures mentioned in the excerpts of Austroads Part 6A at right