Primary and secondary streets
Primary roads/streets carry the most traffic. Cycle traffic will be high on these routes as these will also be the most direct routes between areas.
Significant attention must be given to the design of these streets, as correct design will be crucial for enabling people to cycle.
Secondary streets connect the primary streets to local streets in residential and commercial areas. They are designed for relatively lower volumes of car and cycle traffic. They will be narrower and have lower speeds than the primary streets. As traffic volumes will be lower, less infrastructure is required, and the level of separation of cycles and other vehicles can be lower.
There are three key aspects of infrastructure:
1. Space for cyclingPeople do not like cycling amongst traffic, or mixing with pedestrians. Therefore the primary requirement, which will make cycling an easy choice, is to provide dedicated space for cycling on streets carrying most traffic. At least 2.1m of dedicated cycling space must be provided on each side of the road, with some degree of protection from traffic. |
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2. Priority at sideroadsAll cycle tracks along primary streets should have priority over side roads, including junctions with secondary streets. The cycle track and footway must not change height across this junction. |
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3. JunctionsJunctions are the most common location for collisions. A well-designed junction reduces the number of decisions that need to be made by each road user. Providing space for cycling, that minimises conflict points, will prevent collision blackspots. |
Primary and secondary streets
1. Space for cycling on primary and secondary streets
Space for cycling is the key principle underpinning provision on larger streets
People do not like cycling amongst traffic, or mixing with pedestrians. Therefore the primary requirement, which will give people the choice to be able to cycle, is to provide dedicated space for cycling on streets carrying most traffic. Infrastructure must be suitable for people cycling fast or slowly.
At least 2.1m of space must be provided on both sides of the road, with some degree of protection from traffic. Priority at sideroads (see later) is essential.
The key aspects of this provision are:
Shared-use pavements alongside roads are unacceptable in newly designed streets
- Space away from traffic
- Not mixed with pedestrians
- Careful layout of car parking
- Continuity around bus stops
- Layer separation
- Speed limits of up to 30mph
The two design solutions to achieve space for cycling are:
Option 1: Fully-segregated cycle tracksThe best practice option is the use of segregated cycle tracks. This is the model used very successfully in the Netherlands. These need to be 2.5m wide (minimum 2.1 metres) on both sides of the road, machine-laid, and separated from the main carriageway by at least one metre of green space (or car and cycle parking). Kerbing needs to be forgiving (shallow and/or angled) to avoid accidents, and also to allow the maximum width of track to be used. |
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Option 2: Hybrid cycle lanes: on-road, with an off-road feelingAn alternative option is hybrid cycle lanes. These are found in Denmark and Sweden, and now feature in DfT guidance. They are on-road cycle lanes that have some kind of physical demarcation to provide the feeling of protection that less confident cyclists want. Cobbles or another kind of informal segregation is needed. These 2.5 metre (2.1m minimum) cycle lanes are smooth, and raised slightly above the level of the main road surface. Red tarmac should be used. Footpaths to the side should be a separate construction and raised slightly above the level of the cycle lane. |
What are the key aspects of this provision?
Space away from traffic:Good width, easy to cycle side-by-side. 2.5m width (2.1m minimum). Should have a distinct colour, using coloured tarmac (not painted). Suitable for everyone: fast or slow, novice or experienced, able-bodied or disabled. |
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Not mixed with pedestrians:Remember the three networks: people walking should have their own footpath, separate from the cycle track. |
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Careful layout of car parking:If car parking is required along these streets, it should be adjacent to the main carriageway with the cycle tracks going inside. A width of 2.5m avoids the problem of 'dooring' of cyclists by parking cars. (Narrower width needs a 50cm buffer zone.) Parking bays must always be between the cycle track and the traffic lanes. |
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Continuity around bus stops:Special care must be taken around bus stops. Space must be provided for pedestrians waiting for or exiting a bus. The cycle track must be continuous, away from the waiting area. This layout is sometimes called a 'floating bus stop', and is very common in northern Europe. |
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Layer separation:of the cycle tracks is recommended: higher than the road surface, but lower than the footway. |
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Speed limits of up to 30mph:are appropriate for primary streets if sufficient segregation of cycles is provided. |
Primary and secondary streets
2. Priority at sideroads (meeting secondary streets)
Junctions with sideroads are still important junctions.
Any cycle infrastructure that runs alongside a road must be continuous: in other words, it must maintain priority over every sideroad.
Having to stop and give way at a side road makes cycling much harder work, because of the continual loss of momentum. Imagine how irksome driving would be if there was a traffic light or 'give way' at every side road.
The cycle track and footway must not change height across this junction.
Priority for cycle tracks alongside a road works best when those cycle tracks are uni-directional. This means that drivers do not need to make additional checks for cyclists crossing, because cycles will be going in the same direction as cars.
The adjacent footway should also provide continuity for pedestrians as per the cycle track. This design reinforces the Highway Code rule on pedestrian priority at side roads.
A small waiting area for cars is needed, so that drivers do not block through-traffic while waiting for a cyclist crossing on the opposite side of the road. Raised red crossings are an appropriate way of stressing priority.
For hybrid cycle lanes, simply continue the lane across the junction, as if it were another traffic lane, maintaining the red surfacing.
Primary and secondary streets
3. Junctions on primary and secondary streets
Junctions are the most common location for collisions. A well-designed junction reduces the number of decisions that need to be made by each road user. Providing space for cycling, minimising conflict points, will prevent collision blackspots. Junctions that feel subjectively safe will increase the likelihood of people cycling.
Owing to the lower volumes of traffic, simpler junctions can be used on secondary streets. Multiple lanes of traffic, which are inherently difficult to negotiate by bicycle, should be avoided.
The key requirements for creating safe junctions for cycling which remain convenient and easy to use are:
- Maintaining separation through the junction
- Reducing the number of interactions with other traffic
- Visibility, achieved by the use of perpendicular crossing points
- Avoiding multiple stop-start manoeuvres
- Reducing traffic speeds through the junction.
Maintaining separation through the junctionAllocation of dedicated space for cycling must continue through the junction, so that people experience a joined-up route that avoids unnecessary mixing with traffic. Cycle lanes should be marked across the junction to indicate the space a cyclist requires and to reduce the likelihood of collisions with left-turning vehicles. |
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VisibilityA key principle in safe street design is that a road user never has to look in more than one direction to move safely negotiate part of a junction. This can be achieved by the combination of:
The best practice panel overleaf suggests a video illustrating these important points. |
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Providing cycle refuges on large primary streetsFor maximum safety, cycle tracks should not cross more than one lane of traffic or traffic flowing in multiple directions, without a safe refuge where cyclists can wait. Cycle refuges, at least 2.4 metres in length, should be provided between these traffic lanes. If this is not possible, then signalisation or grade-separation of the cycle routes must be used to provide sufficient safety. |
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Avoiding stop-start manoeuvresHaving to stop and give way constantly makes cycling very tiring and unattractive. Adding blue signs to a pavement around a junction is not in any way an effective or useful cycle facility. |
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Signalised junctionsSignalised junctions should reduce the waiting times for bicycles, by having more frequent but shorter timings for cycle traffic. Waiting times of over 30 seconds make cycling slow and unattractive. The bicycle traffic should have the same direct routes over the junctions that cars do. Consideration should be given to using innovative traffic signals such as: (i) advanced green cycle signals, or (ii) simultaneous green phase for bicycles. |
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Grade separationGrade separation can be provided using tunnels or bridges. Tunnels are preferred but only if the sight lines through the tunnel are sufficient that you can see into and out of the tunnel before entering. Bridges should be as straight as possible with gentle ramps. Consider raising the road up to reduce the depth of the tunnel, or consider lowering the road to reduce the height of the bridge. |
Best practice
Sadly, there are very few junctions in the UK that display best practice for cycling, hence the continuing high level of collisions. Designers must consider looking to solutions employed abroad if junction safety is to be addressed seriously. Increasingly, the DfT is considering allowing these onto UK streets.
Consider using a one-way bicycle-only roundabout with cycle traffic moving clockwise around the outside of the traffic junction.
Note how, in the Dutch design, a standard four-way junction for vehicles effectively has a bicycle roundabout around the outside. This is an example of the principles in practice.
The concepts and design of a Dutch junction are explained in this video: |
The same principles from a US perspective are explained in this video: |