Cycles of all sorts

The CTC/IHT hierarchy

1. Traffic reduction. Can traffic levels particularly that of heavy vehicles be reduced?
2. Traffic calming. Can speed be reduced and driver behaviour modified?
3. Junction treatment and traffic management. These measures include:
   • Urban traffic control systems designed to recognise cyclists and give them priority.
   • Exempt cyclists from banned turns and access restrictions.
   • Provide contra-flow cycle lanes on one-way streets.
   • Implement on-street parking restrictions.
   • Provide advanced stop lines/bypasses for cyclists at traffic signals.
   • Junction alterations, signalise roundabouts, cycle-friendly junction design.
4. Redistribution of the carriageway. Such as by marking wide kerb lanes or shared bus/cycle lanes.
5. Cycle lanes and cycle tracks. Having considered and implemented all the above, what cycle tracks or cycle lanes are considered necessary?

Examples: Traffic reduction

Traffic reduction can include straightforward reduction or alternatively diversion. Diversion involves routing heavy traffic away from roads used by high numbers of cyclists and pedestrians. Examples of diversion include the construction of arterial bypasses and ring roads around urban centres.

Traffic reduction can involve direct or indirect methods. Indirect methods involve reducing the infrastructural capacity dedicated to moving or storing cars. This can involve reducing the number of lanes for cars, closing bridges to motorised traffic and creating vehicle restricted zones or environmental traffic cells. The centre of the Dutch city of Groningen is divided in to four zones that cannot be crossed by private motor-traffic, (private cars must use the ring road instead). Cyclists and other traffic can pass between the zones and cycling accounts for 50%+ of trips in Groningen (which reputedly has the third highest proportion of cycle traffic of any city).

Reducing car parking capacity is an associated method. Starting in the 1970’s, the city of Copenhagen, which is now noted for high cycling levels, adopted a policy of reducing available car parking capacity by several per cent a year. The city of Amsterdam, where around 40% of all trips are by bicycle , adopted similar parking reduction policies in the 80s and 90s. Direct traffic reduction methods can involve straightforward bans or more subtle methods like road pricing schemes. The London congestion charge reportedly resulted in a significant increase in cycle use within the affected area.

Examples: Speed reduction/traffic calming

The town of Hilden in Germany has achieved a rate of 24% of trips being on two wheels[citation_needed], mainly via traffic calming and the use of 30 km/h (20 mph) zones. In the Netherlands, there are over 6000 Woonerven or "Home zones" where cyclists and pedestrians have legal priority over cars and where a motorised speed limit of "walking speed" applies. In contrast, however, some UK and Irish "traffic calming" schemes, particularly involving road narrowings, are viewed as extremely hostile and have been implicated directly in death and injury to cyclists.

Examples: One-way streets

One-way street systems are viewed as a product of urban management that focuses on trying to keep motorised vehicles moving at all costs. If applied to cyclists, they are argued to impose unnecessary trip length and inconvenience. It is argued that there are rarely any traffic management justifications for imposing this restriction on cyclists. In northern Europe, cyclists are frequently granted exemptions from one-way street restrictions. In Belgium, all one-way streets in 50 km/h zones are by default two-way for cyclists. Denmark, a country with high cycling levels, makes no use of such traffic-flow focused one-way systems. Some commentators from cyclist-hostile/car-focused jurisdictions argue that the initial goal should be to dismantle large one-way street systems as a traffic calming/traffic reduction measure, followed by the provision of two-way cyclist access on any one-way streets that remain.

Examples: Junction design

In general, junction designs that favour higher-speed turning, weaving and merging movements by motorists will tend to be hostile for cyclists. Features such as large entry curvature, slip-roads and high flow roundabouts are associated with increased risk of car–cyclist collisions. Research indicates that excessive sightlines at uncontrolled intersections compound these effects. Cycling advocates argue for modifications and alternative junction types that resolve these issues such as reducing kerb radii on street corners, eliminating slip roads and replacing large roundabouts with signalised intersections.

Examples: Traffic signals/Traffic control systems

How traffic signals are designed and implemented also impacts cyclists. A typical issue is the vehicle detector systems which trigger signal changes. Some detection systems do not recognise cyclists or must be carefully adjusted to do so. This can leave cyclists in the position of having to "run" red lights if no motorised vehicle arrives to trigger a signal change. Some cities use urban adaptive traffic control systems (UTC's), which use detectors and traffic signals to manage traffic in response to changes in demand.

There is an argument that using a UTC system merely to provide for increased capacity for private motor traffic will simply drive growth in such traffic. However, there are more direct negative impacts. For instance, where signals are arranged to provide so called green waves for certain classes of vehicle, this can create "red waves" for other road users such as cyclists and public transport services. Such systems may also take system capacity from pedestrians by removing time from pedestrian crossing phases and giving it instead to private motor cars. Cycling-specific measures that can be applied at traffic signals include the use of advanced stop lines and/or bypasses.