When choosing the type of separation device next to a cycleway, the following issues should be considered:
Cycleway separators are designed to keep motor traffic out of the cycleway, however, it will be necessary to allow motor vehicles across the cycleway at certain midblock locations, mainly driveways – it should not be difficult to identify where to provide motor vehicle permeability.
Cyclists will also need access to and from the cycleway at midblock locations to begin and end their trip, or transition to a different road.
Where there are footpaths, pedestrians will also need to cross the cycleway separator.
Installing a separated cycleway may also affect the flow of stormwater.
Height affects ability of users to mount (ie drive or cycling up and over) it (and therefore permeability), and cyclists’ perception of safety.
As well as the height of the device, the slope of its sides affects the ability of motor vehicles to drive over it, cyclists to ride over it, and pedestrians to walk / roll over it; these three users have different requirements and should preferably be provided for at different locations.
Where motor traffic crosses the cycleway, it is important that drivers and cyclists can see each other. The type of separator used may affect the inter-visibility between cyclists and other traffic; for example, a row of parked cars restricts inter-visibility much more than small, intermittent devices such as bollards.
If a row of is higher than driver eye height (1.1 m above the ground), their length and spacing near driveways and intersections should be reviewed, to ensure adequate sight lines are provided.
The set back of separator posts from driveways and intersections and provision for parking is detailed in the technical note on separated cycleways at side roads and driveways [PDF, 2.4 MB].
Painted markings (eg green surfacing or continuity lines) can be used to continue the separation across the gap.
CloseThe side of the separator adjacent to the cycleway should be designed for cyclists’ comfort. Separators higher than pedal height (about 50 mm) cause a ‘shy space’ – ie. cyclists will give the edge of the separator a wider berth. To mitigate this, either:
This criterion is superseded by any requirements for the device to be mountable by users (see Mountable kerb detail), wherever cyclists should be able to ride over the separator.
CloseA wider horizontal buffer between cycleway users and adjacent users (moving traffic, parked cars, pedestrians) increases the level of comfort and safety (perceived and actual) for cyclists (and pedestrians, where they are involved). People accessing and egressing from parked vehicles may require a wide enough separator to comfortably organise themselves (consider especially those with prams, dependent children, or mobility devices).
Wider separators also provide space for infrastructure / amenities such as signage, traffic signal poles, light poles, parking meters, rubbish and recycling bins, trees, seating etc. The following list outlines recommended separator widths:
Between a cycleway and active traffic lane:
Between a cycleway and parking lane:
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Devices need to be visible to road users, during both day and night, so that everyone is aware of the presence of the separators and cycleway. Cycleway designers may sometimes feel in conflict with urban design objectives, which can favour styles that are less conspicuous.
Separation devices will be struck on occasions by motor vehicles, either while driving or manouevring. It is important to choose a product that suits the expected type and frequency of impact – these will depend on the traffic volumes, traffic speed, traffic lane widths, road curvature, visibility and propensity of drivers to try to enter the cycleway (eg in locations where demand for on-street parking exceeds capacity).
New Zealand experience so far has yielded the following observations:
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It is important to regularly and routinely clear debris from separated cycleways.
Points to consider are:
Rubbish / recycling collection trucks need to access bins placed to the side of the road; in some cases, the cycleway separation device may hinder this process.
Involve the local rubbish collection contractor(s) in discussions about accommodating bins when designing the separated cycleway.
Ideally, design with the following components:
If the above cannot be achieved, consider:
The Waste Management Institute New Zealand (WasteMINZ)(external link) has developed guidelines(external link) on how waste collection vehicle operators should operate in the vicinity of cyclists and cycle infrastructure. The guide also includes useful information and tips for cyclists regarding how to interact with waste collection vehicles. Cycleways should be designed with these principles in mind.
CloseIt may be intended that separators are permanent fixtures, or they may only have a temporary function. Maintenance works may also occasionally necessitate temporary removal of separators.
Cast-in-place concrete islands and kerbs are generally permanent solutions, but other separators that are bolted or glued to the ground can also be considered permanent solutions, as long as their materials and fixtures are suitably durable.
A “temporary” separator is intended as an interim solution and will have a relatively short design life at a specific site. Temporary separators are not necessarily disposable; some types of separators may be able to be transferred to other sites and used multiple times, for a variety of purposes. Temporary devices could be installed, for example, to be in place for 2-5 years until a major road upgrade is conducted and permanent separated cycleways are installed, or they could be part of a trial to illustrate to the public what separated cycleways might look like at a site.
The effects of removing the separation device on the road surface should also be considered. In general, any device that requires significant road reconstruction after its removal should not be considered as a viable temporary option. In some site-specific cases, however, if road reconstruction is planned to coincide with the removal of the interim cycleway, this could be considered, especially if the separation device itself could be reused.
Thus, depending on the site and project requirements, most of the separators presented in the separator type chart (except for cast-in-place concrete options) could be considered temporary. In addition, other products could be used, for example the temporary fencing from Shanghai, shown below, which uses connectable units with heavy metal bases that don’t need to be attached to the road surface.
Consider whether the cycleway is being retrofitted to the existing carriageway, or whether there will be significant changes to the carriageway (or even a new carriageway being formed completely). Devices that are attached to the road surface may be more appropriate for retrofit projects, whereas cast-in-place options require the road to be dug up, and so are more suited to projects where significant construction is taking place.
CloseTemporary traffic management during installation is an expensive project component, and disturbances to traffic flow and parking opportunities during construction can induce public opposition to cycleways in general. Therefore, on busy roads or where parking demand is high, ready-made products that quickly attach to the road surface may be preferable to cast in-situ products, due to the amount of time and space required for construction.
CloseIf it is necessary to close a cycleway for maintenance (either to the cycleway, or related to the road environment in general), consider how the cycleway traffic will be provided for. In most cases where a separated cycleway exists, it would not be suitable to expect the target audience for this facility to simply join the motor traffic on the carriageway, unless traffic volumes are low and traffic operating speeds were significantly reduced. It may be necessary to temporary remove some traffic lanes, parking, or other space like flush medians to accommodate a relocated cycleway. In some cases, a temporary shared footpath may be appropriate.
Have generic traffic management plans in place in case a cycleway needs to be closed for maintenance. A key aspect of the plan should be to prescribe the type of temporary separation that will be provided (or appropriate speed management for temporarily shared roadways or paths). This could include the use of temporary posts or barriers to provide a physical separator.
Further information is also summarised in the following document:
Cycleway separation device selection matrix [PDF, 652 KB]