Cycles of all sorts

The issue of the safety of segregated cycling facilities has been one of extreme controversy since the 1930s. Since that time, the established cycling lobby has taken a critical and measured view of their utility and value. On the other hand, the proponents of segregated cycling facilities frequently proclaim them as being necessary to the provision of a "safe" cycling environment. However, in many cases their proponents have no established interest or expertise in cycling promotion and may include representatives of various interests such as the motoring/roads lobbies, traffic engineers, the environmental lobby, political parties, the health sector etc. In contrast to such claims, reviews of the international literature suggest a predominant finding associating the use of roadside urban segregated cycle paths with increases, some significant, in the rate and severity of car/bicycle collisions see Cycle Path Safety Summary of Research. The argument has two sides involving both direct and indirect safety.

Direct safety

Urban roads

The source of the direct safety problem lies in the nature of the predominant car/bicycle collision types. The majority of collisions on urban roads occur at junctions and involve conflicts between turning vehicles. Rear-end type collisions are only a major factor on arterial or interurban roads. Accident analysis suggests that there is merit in providing segregated space for cyclists on arterial routes with few junctions to minimize the number of collisions.

For urban roads, with many junctions, accident analysis suggests the opposite, that segregated cycling facilities are likely to increase collisions. These conclusions are supported by the experience of countries that have implemented segregated cycling facilities. In the U.S., UK, Germany, Swede, Denmark and Finland, it has been found that cycling on roadside urban cycle tracks/sidepaths results in significant, up to 12 fold, increases in the rate of car/bicycle collisions. At a 1991 European conference on cycling, the term Russian roulette was openly used to describe the use of roadside cycle paths.

In Helsinki, research has shown that cyclists are safer cycling on the roads mixed in with the traffic than they are using that city's 800 km of cycle paths See Finnish Research. The Berlin police reputedly came to a similar conclusion in the 1980s. In Berlin 10% of the roads have cycle paths but these produce 75% of the cycling casualties Overview of Berlin situation (in German). In the UK town of Milton Keynes it has been shown that cyclists using the "off-road" cycleway network have, on a per journey basis, a significantly higher rate of fatal car-bicycle collisions than cyclists who simply cycle on the ordinary unsegregated roads Milton Keynes Redway study. Cycle lanes / bike lanes are less dangerous than cycle paths in urban situations but even well-implemented examples have still been associated with 10% increases in casualty rates. However particular concern attaches to the use of cycle lanes in specific urban situations, especially large roundabouts. For adult cyclists, the standard safe cycling advice for handling roundabouts is to try to maintain a prominent position while circulating (Franklin 1997). The use of cycle lanes runs counter to this advice and places cyclists outside the main "zone of observation" of entering motorists; who represent the overwhelming source of risk (50% of collisions) (Layfield and Maycock 1986). In 2002, cycle lanes were removed from a roundabout in the British town of Weymouth after 20 months because the casualty rate had increased significantly (CCN 2002). German research has also indicated that cyclists are safer negotiating roundabouts within the main traffic mix rather than on separate cycle lanes or cycle paths (Schnull et al. 1992). See also cycle facilities at roundabouts.

Rural / Arterial roads

Direct rear impacts with cyclists are a more prominent collision type in arterial/rural road type situations. When they occur in such circumstances they are also associated with significantly increased risk of fatality. Data collated by the OECD indicates that rural locations account for 35% or more of cycling fatalities in Denmark, Finland, France, Great Britain, Japan, the Netherlands and Spain. ^[7] UK police-recorded cycling collision data indicates that at non-junction locations, where a cyclist was struck directly from behind, there was an overall fatality rate of 17%. The risk of fatality increases with speed limit of the road. Where such collisions occurred on 30mph roads a 5% fatality rate was recorded, climbing to 13% at 40mph, 21% at 60mph and a fatality rate of 31% on 70mph roads. ^[8] The use of appropriately designed segregated space on arterial or interurban routes does appear to be associated with reductions in overall risk. In Ireland, the provision of hard shoulders on interurban routes in the 1970s reportedly resulted in a 50% decrease in fatal collisions. It is reported that the Danes have also found that separate cycle tracks lead to a reduction in rural collisions.

Indirect safety

There is robust evidence that one of the main factors influencing the individual safety of cyclists is the base number of cyclists using the roads. See safety in numbers effect. Therefore it is arguable that if a segregated cycle facility does genuinely act to create a more attractive cycling environment, and actually attracts more people to cycle, then this effect should contribute to an overall increase in safety. In addition it has been shown that the health benefits of regular cycling significantly outweigh the risks due to traffic danger. Therefore, any measures that promote cycling should produce an overall societal health benefit. However, given their historical purpose, a positive relationship between the use of segregated cycle facilities and increased cyclist numbers cannot be assumed.

The "safety in numbers" argument can also be used to explain the apparent success of cycle facilities in some cities. In most cases, the most prominent examples of "successful" cycle networks were implemented in towns that already had significant numbers of cyclists. It can be argued that in such cases this existing large cycling population already exerted a strong "safety in numbers" effect, which continued to operate despite their diversion onto off-road tracks. Conversely, cycle-network sceptics argue that when imposed in low cycling environments, similar measures will have a greater tendency to increase danger by attenuating whatever limited effect the existing cyclist population was exerting.

Remedial measures

Various remedial measures have been developed in an attempt to solve the identified safety problems of segregated cycle facilities. Examples include the addition of a separate system of traffic signals for bicycle traffic. This can get extremely complex, particularly if there are already separate traffic signal phases for pedestrians, motorised traffic and public transport modes such as trams and/or buses. The need for a separate system of traffic lights also means that building a functioning, completely segregated, cycle path system is a non-trivial exercise in terms both expense and engineering effort. In addition, various road markings have been developed in an attempt to remedy the issue of increased junction collisions. Examples of these include the use of special road markings e.g. "elephants footprints" and special coloured treatments using red, green or blue coloured tarmac. Such treatments are often proclaimed as safety "improvements" . However, cycle-facility sceptics view such claims as, at best, disingenuous. They argue that in many cases the actual purpose is to "restore" the level of safety that existed before the marking/construction of the segregated cycle facility.