Segregated cycle facilities

Segregated cycle facilities are a form of cycling infrastructure consisting of marked lanes, tracks, shoulders and paths designated for use by cyclists and from which motorised traffic is generally excluded. The term includes bike lanes, cycle tracks, separated bike lanes, road shoulders and side paths located within a road right-of-way.

The names and definitions of the various cycle facility types vary from country to country, but besides local naming conventions, one of the main subdivisions is whether the facility is physically separated by barriers, parking or bollards from other (especially motor vehicle) traffic, or whether the segregation is due to painted markings. The facilities have been modified over time and increased in variety as usage changes, and as cities receive feedback and experiment with improvements.

Bike lanes and road shoulders demarcated by a painted marking are quite common both in many European and American cities. Segregated cycle facilities demarcated by barriers, bollards or boulevards are quite common in some European countries such as the Netherlands, Denmark and Germany. They are also increasingly being installed in other major cities such as New York City, Melbourne, Vancouver, Ottawa, Toronto and San Francisco. Montreal and Davis, California, which have had segregated cycling facilities with barriers for several decades, are among the earliest examples in North American cities.

Terminology
Various guides exist to define the different types of bikeway infrastructure, including UK Department for Transport manual The Geometric Design of Pedestrian, Cycle and Equestrian Routes, the Danish Road Authority guide Registration and classification of paths, the Dutch CROW, the American Association of State Highway and Transportation Officials (AASHTO) Guide to Bikeway Facilities, the Federal Highway Administration (FHWA) Manual on Uniform Traffic Control Devices (MUTCD), and the US National Association of City Transportation Officials (NACTO) Urban Bikeway Design Guide.

On road: bike/cycle lanes
Cycle lanes (UK) or bike lanes (USA) are lanes, for cyclists only, marked on an existing portion of a carriageway (UK) or roadway (USA).
 * A cycle lane (UK) is a traffic lane marked on an existing roadway or carriageway and generally restricted to cycle traffic. It can be mandatory (marked with a solid white line, entry by motor vehicles is prohibited) or advisory (marked with a broken white line, entry by motor vehicles is permitted).
 * In the U.S., a designated bicycle lane (1988 MUTCD) or class II bikeway (Caltrans) is a portion of a roadway which is separated from traffic lanes by the use of a solid white stripe on the pavement and has been designated for preferential use by bicyclists. A class III bicycle route has roadside signs suggesting a route for cyclists, and urging sharing the road.

On road: cycle track
A cycle track is an exclusive bike facility that has elements of a separated path and on-road bike lane. A cycle track, while still within the roadway, is physically separated from motor traffic and is distinct from the sidewalk.

Cycle tracks may be one-way or two-way, and may be at road level, at sidewalk level, or at an intermediate level. They all share in common some separation from motor traffic with bollards, car parking, barriers or boulevards.

In the UK, cycle track is a roadway constructed specifically for use by cyclists, but not by any other vehicles. In Ireland cycle track also covers cycle lanes marked on the carriageway but only if accompanied by a specific sign. In the UK, a cycle track may be alongside a roadway (or carriageway) for all vehicles or it may be on its own alignment. The term does not include cycle lanes or other facilities within an all-vehicle carriageway.

Off road: shoulder
A road shoulder is a reserved area outside of a roadway, but within the road right-of-way. Road shoulders (a) are a buffer area between the roadway and possible off-road hazards intended to prevent accidents in the event of a temporary loss of vehicle control, (b) provide emergency access for ambulances and police cars and (c) provide a space for inoperable vehicles so that they do not block the traveled way. In addition, road shoulders are used by bicyclists when other bicycle-specific facilities are absent, or inferior.

Off road: sidepath / shared-use footway
A sidepath or typically referred to as a shared use path in the US is a path or sidewalk that has been designated for use by cyclists within the right of way of a public road but outside of the roadway. It is usually not immediately adjacent to the portion of the way for vehicular traffic, that is, the traveled portion of the roadway. It may or may not have a center divider or stripe to prevent head-on collisions.

A shared-use footway is for use by both cyclists and pedestrians in the UK and will usually be to a lower standard than a cycle track. While cyclists may be required to yield right of way to foot traffic on a shared-use footway which is unsegregated, that is, where both types mix freely, cyclists are usually considered to be the primary users on cycle tracks. Note that the design standards and recommendations for shared-use footways and cycle tracks in the UK are different from those for shared-use paths in the U.S.

Segregated facilities and safety
Segregated cycling facilities are controversial, in particular concerning safety. Proponents tout segregation of cyclists as necessary to the provision of a safe cycling environment, as some recent research has suggested. A 2010 Montreal study found that cycle tracks resulted in fewer injuries when compared to what the study claimed were comparable parallel roads with no cycling facilities.

There have been a number of studies of research into the risks and benefits of segregated cycling facilities that have drawn different conclusions. Recent research, such as the 2010 Montreal study, suggests a lower risk for cyclists using cycling-specific infrastructure in certain traffic dynamics, though there has been also research suggesting that cycling-specific infrastructure raises the risk for cyclists. A 2006 report by the National Cooperative Highway Research Program in the UK concludes that "bicycle safety data are difficult to analyse, mostly because bicycle trip data (and thus accident probability per trip) are hard to uncover". One major reason for the inability to draw definite conclusion may be that facilities with different risks are often categorized together so that off-road paths – paved or unpaved, bicycle-only or multi-use – were lumped together, as found by research at the Cycling in Cities program at the University of British Columbia.

Studies showing greater benefits


The UBC Cycling in Cities Research Program, in their 2009 review of the scientific literature of bicycle facilities, elaborated on why it is difficult to determine the risk of different route types: "It may be straightforward to count the injuries that occur on different route types (numerator data), but it is more difficult to gather data on the number of cyclists who use various route types (the denominator data needed to calculate the risk)." When they were able to look at injury and crash data separated by bicycle facility type, they found the evidence suggested that "purpose-built bicycle-only facilities have the lowest risk of crashes and injuries". They found such bike-only facilities had lower risk than cycling on-road with motor traffic as well as off-road with pedestrians on sidewalks or multi-use paths. The highest risk of crashes and injuries were found to be on sidewalks and unpaved off-road trails.

A large study undertaken by S.U. Jensen et al. into the safety of Copenhagen cycle tracks before and after they were constructed concludes "The construction of cycle tracks in Copenhagen has resulted in an increase in cycle traffic of 18–20% and a decline in car traffic of 9–10%. The cycle tracks constructed have resulted in increases in accidents and injuries of 9–10% on the reconstructed roads." The increase of accidents and injuries increased at intersections while decreased mid-block.

Even though it appears from this study that cycle tracks decrease safety, from the perspective of an individual cyclist, claims Dr. Lon D. Roberts, the Copenhagen study shows that the "likelihood an individual bicyclist will experience an accident goes down as the number of bicycle riders go up". That is because cycle traffic increased in this study at a faster rate than the rate of accidents and injuries. Roberts states: Using Soren’s percentages, here’s an example starting with the assumption that 10 bicyclists out of 10,000 will experience an accident over a certain period of time if there are no bike tracks:


 * 1) On an individual basis, there’s a 10 out of 10,000 (or 0.1%) chance that an individual biker will experience an accident if there are no bike tracks
 * 2) When the bike tracks were added, the accident rate increased by 9%. In other words, if there are 10 accidents without the tracks, the number of accidents increases 10.9 (or approximately 11). On the other hand, the number of bike riders increased by 18%, from 10,000 to 11,800. Therefore, on an individual basis the likelihood of an accident with the tracks added is now 11 out of 11,800, or 0.09%, as opposed to 0.1% without the lanes/tracks.

The Copenhagen study also found accident and injury rates were related to the amount of car parking, turn lanes, blue cycle crossing markings, and raised exits at non-signalised intersections, suggesting that risk is dependent on making various improvements to the cycle tracks. For instance, recent planning guidelines in the US advise that cycle tracks drop to a bike lane before arriving at an intersection to increase the visibility of cyclists.

A 2010 study in Montreal, Canada, by Lusk et al., compared the motor vehicle-bicycle crashes and injuries on six Montreal cycle tracks (physically separated bicycle-exclusive paths along roads) with comparable reference roads (a parallel road with approximately the same intersection frequency and cross traffic). The authors found 2.5 times as many cyclists rode on the cycle tracks compared to the reference roads. They also found that the relative risk of injury was lower on a cycle track than on the comparable reference road (the average being 0.72 the relative risk). They concluded that "[c]ycle tracks lessen, or at least do not increase, crash and injury rates compared to bicycling in the street"

A 2012 study by the Cycling in Cities Research Program at the University of British Columbia, Route Infrastructure and the Risk of Injuries to Bicyclists: A Case-Crossover Study, analyzed the cause of 690 cycling injuries and compared the risk of injury of cycling on 14 different types of route and route infrastructure features, and found that cycling on segregated tracks had approximately one ninth the risk of cycling on major streets with parked cars and no cycle infrastructure. It concluded that "The lower risks on quiet streets and with bike-specific infrastructure along busy streets support the route-design approach used in many northern European countries. Transportation infrastructure with lower bicycling injury risks merits public health support to reduce injuries and promote cycling."

The New York City Department of Transportation implemented a bicycle path and traffic calming pilot project for Prospect Park West in Brooklyn in 2010 and published their results in early 2011. It created a two-way bicycle path with a three-foot parking lane buffer and the removal of one lane from motor vehicles. They found that weekday cycling traffic tripled after the implementation; cyclists riding on the sidewalk fell to 3% from 46% (the count included children who are legally allowed to ride on the sidewalk); speeding dropped from 74% to 20% of all vehicles; crashes for all road users were down 16% and injuries to all road users were down 21%.

An unfunded 1997 study by William E. Moritz of North American bicycle commuters calculated a relative danger of different facilities based on the survey results of "[fraction of crashes] divided by the [fraction of miles ridden on that facility]". Moritz calculated a relative danger of 1.26 on a major street with no cycling facilities, 1.04 on a minor street with no cycling facilities, 0.5 for streets with bike lanes, and 0.67 for mixed use/"bike" path. The "other" category which mostly included sidewalks had a relative danger of 5.32. Moritz made it clear that this was "[n]ot a statistical or random sample of BCs [bicycle commuters]."

Transportation engineers Ian Hallett, David Luskin, and Randy Machemehl, by studying the interactions of drivers and bicyclists on Texas roads, have discovered that having painted bike lanes on streets and roads helps both commuters stay in safer, more central positions in their respective lanes. Without a marked bike lane, there appears to be a lot of uncertainty about how much space each person needs—even when adequate road space is provided.

Studies showing greater risks
In the 1970s, the California Statewide Bicycle Committee arranged with Kenneth D. Cross for a study of car-bike collisions, expecting that this study would support their arguments on collision prevention. When presented to the Committee in Sacramento on 19 June 1974, Cross's study showed the opposite: 0.5% of car-bike collisions had occurred between straight-ahead cyclists and overtaking straight-ahead motorists. Cross in 1977 had a contract with the National Highway Traffic Safety Administration (NHTSA) to produce an improved study (on a pseudo-random national sample), and the results were much the same.

From the second Cross study, it states "Consequently, although a reduction in overtaking accidents may not be sufficient justification for the widespread use of on-street bicycle lanes, it is possible that their cost could be justified when considering all the problem types that might be positively affected by such facilities. There is virtually no doubt that off-street bicycle lanes would reduce the incidence of overtaking accidents, if such facilities were available and used by bicyclists who would otherwise be riding on roadways."

A 1994 study in Palo Alto, California by A. Wachtel and D. Lewiston concluded that "Bicyclists on a sidewalk or bicycle path incur greater risk than those on the roadway (on average 1.8 times as great), most likely because of blind conflicts at intersections. Wrong-way sidewalk bicyclists are at even greater risk, and sidewalk bicycling appears to increase the incidence of wrong-way travel." and "Separation of bicycles and motor vehicles leads to blind conflicts at these intersections." It concluded "the aim of a well-designed roadway system should be to integrate bicycles and motor vehicles according to the well-established and effective principles of traffic law and engineering, not to separate them. This conclusion is in accord with the 1981 and 1991 AASHTO Guides and the California Highway Design Manual".

Anne C. Lusk et al. noted that the study by Wachtel and Lewiston only considered intersection crashes, "omitting non-intersection crashes that include being hit from behind, sideswiped, or struck by a car door." If the non-intersection crash data is included, as Lusk et al. calculated in their study, it appears that sidewalk bikeways carry half the risk of the street, for bicyclists riding in the same direction as traffic. Lusk et al. claim that the "Wachtel and Lewiston data, when corrected to include non-intersection crashes, corroborate our findings that separated paths are safer or at least no more dangerous than bicycling in the street."

Aultman-Hall et al. produced a 1998 study based on a survey of Ottawa commuter cyclists and a survey of Toronto commuter cyclists. The surveys were conducted to create "estimates of travel exposure on roads, off-road paths and sidewalks". They found that "the relative rates for falls and injuries suggest it is safest to cycle on-road followed by off-road paths and trails, and finally least safe on sidewalks." The relative rates of collisions on the three different facility types, however, were not statistically significant in the Ottawa study. Aultman-Hall et al. admitted that the limitations to the data and a fuller analysis needed "bicycle travel exposure information and the use of more than just collision databases".

A Danish study by Agerholm et al. in 2008 concluded that "Through the years many studies have shown that bicycle paths in built-up areas impair traffic safety. A new Danish study presented in this article confirms these results... the main results are that bicycle paths impair traffic safety and this is mainly due to more accidents at intersections, and that there has been no improvement in the design of new bicycle paths compared to the older ones."

Researchers in other countries have pointed to risk implications of cycle tracks. In Germany, for instance, the Berlin police conducted a 1987 study which came to a negative conclusion about cycle tracks. The German Cycling Federation at the 1990 Vélo Secur conference on cycling claimed "Because the separation of different types of traffic by means of sidepaths behind curbs makes excessive demands on users and leads to crashes, other solutions are being increasingly recommended for channeling bicycle traffic." The cycle tracks in Berlin, however, were not removed and Berlin continues to have an extensive network of bicycle facilities on- and off-road, including cycle tracks.

Studies that also found negative safety aspects of cycle tracks also come from Linderholm, Sweden, 1984 and from Jensen et al., Denmark 1997. In the United Kingdom, the UK Cycle Campaign Network made a 2007 statement that they know "of no evidence that cycle facilities and in particular cycle lanes, generally lead to safer conditions for cycling".

British cycling safety educator John Franklin argues that the vast majority of research implies increases in the rate and severity of car-bicycle collisions due to such segregation, based on an overview of studies published up to 1999. Franklin's background is in IT and cycling education and, though he has presented papers and had some published, none were published in peer-reviewed scientific papers. His work in this field is often disputed by cycling advocates and bloggers as being unscientific and biased towards on-road cycling.

Motorists overtaking crashes
One benefit of cycle tracks is the reduction of motorist-overtaking collisions. There are more rear impacts with cyclists in arterial/rural-type roads. When they occur in such circumstances, they are also associated with significantly increased risk of fatality. Rear-end type collisions by overtaking motorists who didn't see the cyclist (Type 13 in the Cross-Fisher study) have been characterized as negligible in one analysis by John Forester and another analysis by Kenneth Cross characterized them as being the most deadly of crashes – three time the fatalities of other crash types (both used the same data). All motorist overtaking crashes were combined by Cross into a category called "Problem Class D–Motorist Overtaking/Overtaking Threat" accounting for 37.8% of fatal crashes and 10.5% of non-fatal crashes in their study. One possible explanation for the low overall number of collisions is that motorists coming from behind have plenty of time to see and avoid the collision, but another "possible explanation for the low number of overtaking collisions is that, as noted earlier, bicyclists fear and avoid roads where the overtaking threat seems greatest". Though such crashes were not in the majority they both had a perception of being quite dangerous by the majority of cyclists as well as having a high percentage of the fatal crashes.

In the UK, cycling collision data recorded by police indicates that at non-junction locations, where a cyclist was struck directly from behind there was an overall fatality rate of 17%. The rate of fatality increases with speed limit of the road:
 * 5% on 30 mph,
 * 13% on 40 mph,
 * 21% on 60 mph and
 * 31% on 70 mph roads.

The use of appropriately designed segregated space on arterial or interurban routes appears 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 accidents. It is reported that the Danes have also found that separate cycle tracks lead to a reduction in rural collisions.

Junctions
The majority of crashes take place at junctions so there is a risk of crashes where cycle paths meet roads. In the Crash-Type Manual by Tan (following a similar categorization to Cross-Fisher) the majority (approximately 2/3) of all crashes on urban roads occurred at junctions.

When the path entrance is set back from the road, motorists often have difficulty seeing cyclists approaching from the path. Research presented at a conference at Lund University in 1990 found that "crash risk" for cycle users crossing the intersection on a set-back path are up to 11.9 times higher than when cycling on the roadway in a bike lane (see diagrams).

Various remedial measures have been developed in an attempt to reduce the risk of junctions for cycle tracks. In some environments these represent established engineering practice while in others they may have to be retroactively applied in response to complaints and safety concerns. Examples include the addition of a separate system of traffic signals for bicycle traffic; markings – either coloured or sharrows continued through the intersection; bike boxes with no right turn on red lights for motorists, raised intersections, and elimination of car parking or the barrier as the cycle track approaches the intersection.

Some treatments involve raising the cycle track onto a speed ramp-type structure where it crosses side roads. 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. "sharks teeth" or "elephants footprints", and treatments using red, green or blue coloured tarmac.

Some absurd anti-cycling approaches include efforts to "traffic calm" only bicycle traffic by introducing tight curves or bends to slow the cyclists down as they near a junction, but none for cars, which travel much faster. Alternatively, traffic engineers may remove priority from the cyclists and require them to yield to turning traffic at every side road. In 2002, engineers even proposing a sidepath scheme in the Irish university city of Galway stated that cyclists would be required to dismount and "become pedestrians" at every junction on the finished route, rendering cycling as a viable mode of transport completely impractical.

Roundabouts and cycle lanes/tracks
See also cycle facilities at roundabouts.

In the United Kingdom and Germany there is some concern to the use of cycle lanes in large urban roundabouts, though it is still common to see such facilities in the Netherlands and elsewhere. In 2002, cycle lanes were removed from a roundabout in the English town of Weymouth after 20 months because the casualty rate had increased significantly, according to the local cycling campaign. German research has indicated that cyclists are safer negotiating roundabouts in traffic rather than on separate cycle lanes or cycle paths. A recent paper on German roundabout design practice states "Cycle lanes at the peripheral margin of the circle are not allowed since they are very dangerous to cyclists".

In the Netherlands, researchers focused on separating bicycle tracks from motorised traffic. They found that "roundabouts with separate bicycle tracks have a much lower number of casualties per roundabout than roundabouts with bicycle lanes, van Minnen (1995)". This meant that Dutch planners focused more on designing roundabouts and cycle tracks with appropriate priority rather than mix cyclists with other traffic or put them on cycle lanes at the edge.

For adults, the standard advice in the vehicular cycling philosophy for handling roundabouts is to try to maintain a prominent position while circulating. The use of cycle lanes runs counter to this vehicular cycling approach and places cyclists outside the main "zone of observation" of entering motorists, who represent the major source risk.

Safety in numbers effect
There is evidence that one of the main factors influencing the individual safety of cyclists is the number of cyclists using the roads, commonly called the safety in numbers effect. Cycling facilities increase the perception of safety, leaving aside the evidence supporting or detracting from their actual risk. Cycling increases on routes with cycling facilities, particularly if they are separated cycle tracks. With greater numbers of cyclists in relation to motorists, the safety in number effect is seen.

A wide ranging study by P L Jacobsen found that as cycling and walking increase, the chance that a given cyclist will be struck by a motor vehicle actually decreases. This pattern is consistent across communities of varying size, from specific intersections to cities and countries, and across time periods. Jacobsen found that doubling the number of cyclists on the road tends to bring about a 1/3 drop in the per-cyclist frequency of a crash with a motor vehicle. By the same token, tripling the rate of cycling cuts the crash rate in half. A study of the accident impacts of re-engineering bicycle crossings in the Swedish city of Gothenburg appears to corroborate those findings by attributing collision rate reductions in part to significant increases in cyclist volumes at the treated sites.

Detractors argue that the most prominent examples of "successful" cycle networks were implemented in towns that already had significant numbers of cyclists. In such cases, it is speculated that an existing large cycling population might already exert a "safety in numbers" effect, and it is this, rather than their diversion onto off-road tracks, that accounts for the better safety record. More people might start cycling if the perceived safety of doing so improved sufficiently.

Health benefits
In addition, it has been shown that in western countries the health benefits of regular cycling significantly outweigh the risks due to traffic danger. Therefore, notwithstanding their effect on crashes and injuries, measures that promote cycling should produce an overall societal health benefit.

Dutch analysts have argued as a statistical exercise that given that three times as many cyclists as car occupants are injured in collisions, and that cars harm about three times the number of other road users that bicycles do, in situations where casualties due to car traffic predominate, increasing the number of cycling journeys and reducing the number of car journeys will reduce the total number of casualties



With the number of cyclists growing due to the bike lanes, it would create less pollution in the air, causing fewer children with health problems including asthma.

Shared space
Segregated cycle facilities are one way to improve the perception of safety. There are other approaches, such as shared space, which improve actual safety in part by decreasing the difference between real and perceived safety. More recently, shared space redesigns of urban streets in Denmark and the Netherlands have arguably achieved significant improvements in safety (as well as congestion and quality of life) by replacing segregated facilities with integrated space. Traffic reform advocates including David Engwicht and John Adams suggest that the added perception of risk among all road users – motorists, cyclists and pedestrians – in shared facilities increases safety. See the Utility cycling article for other examples of measures to improve both actual and perceived safety.

Road traffic legislation and its implications
One of the potential pitfalls for observers trying to interpret the operation of segregated cycle facilities is that the same legal assumptions do not apply in all environments. For instance, in contrast to most English speaking countries, some European countries, including Germany, France, Denmark, Belgium, and the Netherlands have defined liability legislation. Thus there is a legal assumption that motorists are automatically considered liable in law for any injuries that occur if they collide with a cyclist. This may hold regardless of any fault on the part of the cyclist and may significantly affect the behaviour of motorists when they encounter cyclists. In some countries it is legal for cyclists to overtake motor-vehicles on the inside, and cyclists doing so may enjoy the protection of the law. In this case, the use of segregated cycle facilities conforms to existing traffic law. In other jurisdictions similar "undertaking" manoeuvres by cyclists are illegal. Such distinctions form the basis of the argument that segregated cycle facilities encourage behaviours that flout existing traffic law and in which cyclists enjoy no legal protection.

This variation also applies to the operation of traffic signals and cyclist-specific traffic lights. For instance, in Germany and elsewhere at junctions with segregated facilities all the traffic in a given direction (motorists, pedestrians and cyclists) may get a green signal at the same time. Turning motor traffic is obliged to wait for cyclists and pedestrians to clear the junction before proceeding. In this situation all the transport modes get equal green time. In contrast, UK and Irish practice restricts pedestrians to a dedicated signal phase, separate from and usually much shorter than the green phase for motorists (e.g. 6–12 seconds, vs. signal cycle times of up to 120 seconds). If cyclists were to be segregated and treated in a similar manner this would imply a significant reduction in green time for cycle traffic at every junction. In the English city of Cambridge the use of cyclist-specific traffic signals is reported to have resulted in increased delays for cyclists, leading some to ignore the cycle-facilities and stay on the road. A similar example occurred in a Parisian bikepath scheme in 1999. Cyclists faced twice the number of traffic signals as motorised traffic and were expected to wait over one minute to get seven seconds of green time. Conversely, in Copenhagen cyclist-specific traffic signals on a major arterial bike lane have been linked to provide "green waves" for rush hour cycle-traffic.

Context controversy
Some detractors argue that one must be careful in interpreting the operation of segregated cycle facilities across different designs and contexts; what works for the Netherlands won't necessarily work elsewhere. Proponents argue that segregated cycle facilities have been implemented and are both popular and safe.

The Netherlands, detractors argue, is a flat country and the compact design of Dutch towns keeps cycling distances short as reflected in the Dutch people's choice of bicycle, i.e. the typical Dutch roadster, which has either no gears or a three-speed hub gear and back pedal brakes. Other countries may have different common urban designs, such as sprawling suburbs, and different cycling cultures where riders may ride bicycles with a wider range of gears and like to travel more quickly, such as those who cycle regularly for sport and exercise, who may choose to ride to incorporate some aerobic exercise into their day. So, while a sidepath system may work for slower cyclists, detractors argue, they might not work for cyclists using faster bicycle types who cannot use such a system safely at their higher normal cycling speeds. However, this is contradicted by members of the Royal Dutch Cycling Union, who state that Dutch competitive cyclists have no problems with training in the Netherlands. The Danish Roads Directorate state that the cycle track system "functions best when cyclists travel at relatively low speeds" but what is meant by 'relatively low speeds' is not made clear. There are instances where cycle tracks / sidepaths can accommodate fast cycling as evidenced in this video of a velomobile on a Dutch cycle track.

As more cycle tracks are built in North American cities, more research is being conducted on the uptake and safety of cycle tracks. North American cities that have recently installed cycle tracks have seen significant growth in cyclists using these roads. It is useful, therefore, to use North American examples of cycle tracks/side paths and compare them to similar roads used by cyclists. This will provide better data using cyclists on similar terrain and presumably similar bicycles and experience.



Cycling activists in favour of vehicular cycling have opposed cycle tracks and paths on the principle that they might be created with the "fast cyclist type" in mind. The UK’s Sustrans guidelines for the National Cycle Network are based on recreational use with a design user who is an unaccompanied twelve-year-old. The Dublin Transportation Office has advertised their cycle facilities as being based on an unaccompanied ten-year-old design user. This raises the issue of what happens if different cyclist types find themselves forced onto such devices either by legal coercion or as a result of motorist aggression. This issue is captured in a 1996 review of the Sustrans approach from the Proceedings of the Institution of Civil Engineers. "The fast cycle commuter must not be driven off the highway onto a route that is designed for a 12-year-old or a novice on a leisure trip, because if that happens, the whole attempt to enlarge the use of the bicycle will have failed"

Maintenance controversy


Facilities must be made wide enough for the street sweepers and snow plows typically used in a locale, or the locale will need to ensure that they are regularly swept or plowed by machines that will fit.

Some locales have issues with debris in the cycle paths, such as Milton Keynes, UK, finding that cycle path users are seven times more likely to get punctures than are road cyclists. In Ireland some cyclists have demanded simultaneous commitment to maintenance and sweeping as cycle paths are built.

In areas subject to high leaf-fall in autumn, or high snowfall in winter, any cycle facilities must be subject to regular clearing if they are to remain usable. Danish guidance specifies three different categories of cycle track. Category "A" tracks must be kept clear of snow 24 hours a day, category "B" tracks are swept or cleared daily, and category "C" receive less regular winter maintenance. In 2007 the city of Copenhagen spent DKK 9.9 million (US$1.72 million, €1.33 million) annually on maintaining its cycle track network. German federal law requires local authorities to declassify cycle tracks that do not conform to strict design and maintenance criteria. In the UK, facilities for non-motorized traffic are not normally salted or gritted in icy conditions, potentially making them dangerous or unrideable.

Cycle lanes avoid this problem, as they are part of the road and can be easily accessed by maintenance vehicles operating on that road, incuring no extra cost. They only becomes filled with debris if the road is not maintained or the lane is purposely avoided.

Tracks used at night can be illuminated by conventional means, or by paving with glowing material.

Usage controversy
There are many factors, such as cycle tracks and other cycling infrastructure, which contribute to cycling levels. A number of cities have demonstrated that particular cycle tracks will increase bike traffic on those routes, as shown, for example, in Montreal, New York City and Copenhagen. Bike usage increased by 40% in areas of Montreal where the city invested in bike paths and lanes. In Copenhagen bike traffic increased by about 20% because of the construction of cycle tracks. The construction of separated bike lanes on Dunsmuir Street and Viaduct in Vancouver, Canada, saw bike traffic volumes on the street more than double from before the construction. NYC likewise saw cycling rates nearly triple on weekdays and doubled on weekends when the bike path was installed alongside Prospect Park West.

Seville, Spain, is an example of what is possible on a city scale when a large investment is made in cycling infrastructure over a short period of time. In 2006 there were around 6000 bike trips made daily in the city of around 700,000. By 2009 there were about 50,000 daily bike trips. During those three years 8 urban bike paths totaling 70 km were built; the city centre was closed to motorised traffic; school projects were funded to create safe school paths; traffic calming measures were provided in school districts and the bicycle sharing system ‘Sevici’ was launched. The combination of all these factors helped to create a dramatic change in cycling rates.

After a certain trip modal share it may take more than just installing cycle tracks to create large increases in cycle rates. Cycling rates in the Netherlands peaked in the 1960s and dropped dramatically until the mid-1970s. The decline in bicycle use was "not only caused by mass motorization but also by the related, fairly unco-ordinated process of urbanization and by scores of social, spatial and economic developments", such as a decrease in population density and increased travel distances. The bicycle was almost completely left out of the national government's vision. Certain cities, however, such as Amsterdam and Eindhoven, were slowly implementing more bicycle-positive policies: for example, bike-only streets and allowing cyclists to ignore one way streets. Throughout the 70s cycling rates increased, but the investments in bike paths made in the subsequent period had less effect. Between the late 1980s and early 1990s the Netherlands spent 1.5 billion guilders (US$945 million) on cycling infrastructure, yet cycling levels stayed practically the same.

When the flagship Delft Bicycle Route project was evaluated, the Institute for Road Safety Research claimed that the results were "not very positive: bicycle use had not increased, neither had the road safety. A route network of bicycle facilities has, apparently, no added value for bicycle use or road safety". The study by Louisse, C.J. et al. however, did find that "[a]lthough the total number of victims among cyclists did not decline, the percentage of fatalities and severely injured did drop dramatically." A more comprehensive policy change in addition to bicycle routes, on the other hand, helped to raise the cycling rates in Groningen where 75% of all traffic is by bike or foot. Groningen focused on land use policy, city planning and economic policy changes to achieve very high cycling rates.

In the UK, a ten-year study of the effect of cycle facilities in eight towns and cities found no evidence that they had resulted in any diversion from other transport modes. The construction of 320 km of "Strategic cycle network" in Dublin has been accompanied by a 15% fall in commuter cycling and 40% falls in cycling by second and third level students.

In some locales bike traffic increases first and bike paths and lanes are installed in order to catch up to the demand. For instance, bike planning in Davis, California was driven by the prior existence of a "dramatic volume" of cyclists in the 1960s. Research on the German bicycle boom of the 1980s paints a picture of German local authorities struggling to keep up with the growth of cycling rather than this growth being driven by their interventions. In relation to the UK, it has been argued that locally high levels of cycling are more likely to result from factors other than cycle facilities. These include an existing cycling culture and historically high levels of cycle use, compact urban forms, lack of hills and lack of barriers such as high speed intersections.

However, Pucher and Buehler, U.S.-based researchers, have stated that "the provision of separate cycling facilities" appears to be one of the keys to the achieving of high levels of cycling in the Netherlands, Denmark and Germany.

Segregating cyclists controversy
In some cases, cycle paths have been constructed so bicycles could be prohibited from the main roadway. There is a debate among cyclists as to whether this is for the benefit of motorists or bicyclists.

In 1996 the UK Cyclists' Touring Club and the Institute of Highways and Transportation jointly produced a set of Cycle-Friendly Infrastructure guidelines that placed segregated cycling facilities at the bottom of the hierarchy of measures designed to promote cycling. Planners at the Directorate Infrastructure Traffic and Transport in Amsterdam place cyclists and motorists together on roads with speed limits at or below 30 km/h, and segregate them through bicycle lanes at higher limits. This is in a context where most of the measures prioritised by Cycle-Friendly Infrastructure (HGV restrictions, area-wide traffic calming, speed limit enforcement etc.) are already in place – see Utility cycling for more detail.

Bikeways that use independent rights-of-way
Bike paths that follow independent rights-of-way are less controversial. Such paths are often used to promote recreational cycling. In Northern European countries, cycling tourism represents a significant proportion of overall tourist activity. Extensive interurban bike path networks can be found in countries such as Denmark or the Netherlands, which has had a national system of cycle routes since 1993. These networks may use routes dedicated exclusively to cycle traffic or minor rural roads whose use is otherwise restricted to local motor traffic and agricultural machinery. The UK has recently implemented the National Cycle Network.

Where available these routes are often rail trails making use of abandoned railway corridors. A prominent example in the UK is the Bristol & Bath Railway Path, a 13 mi bike path that is part of National Cycle Route 4. Other UK examples include The Ebury Way Cycle Path, The Alban Way, the Hillend Loch Railway Path and the Nicky Line. In 2003 the longest continuous bike path in Europe was opened, along the Albacete-Valdeganga highway in Spain, a distance of 22 km. Bogota's Bike Paths Network (Ciclorutas de Bogotá in Spanish), designed and built during the administration of Mayor Enrique Peñalosa attracts significant recreational use.



The relative safety of bike paths that follow independent rights-of-way closed to motorized traffic is difficult to assess. In terms of car/bicycle collisions, this is clearly mediated by how the bike path network rejoins the main road network. In the English town of Milton Keynes, a study showed that cyclists using the off-road Milton Keynes redway system had on a per-journey basis a significantly higher rate of fatal car-bicycle collisions at path/roadway crossings than cyclists on ordinary roads.

The consequences of other risks — falls, cyclist–cyclist collisions and cyclist–pedestrian collisions — are frequently not recorded in official accident figures and may be available only via local hospital surveys. As a general rule those bike paths with the highest perceived safety tend to be those engineered on the assumption of vehicular rather than pedestrian traffic. Thus the most popular examples tend to be converted road or railway alignments or constructed to the same standards used by road and railway engineers.

Other bikeways
Other types of bikeway infrastructure are also in use by cities. They are often used for different reasons: the locale may have a different planning philosophy, for example, officials may conclude that the balance of evidence is that segregated facilities are unsafe; the street may be too narrow for bike lanes or cycle tracks; the location may be inappropriate; or for political reasons it may be easier to install something other than a segregated cycle facility. They include:
 * Shared space – Urban design concept that removes traditional segregation among motor vehicles, pedestrians and cyclists and replaces with more "people-oriented" infrastructure.
 * Sharrows – Usually a bike symbol with chevrons painted in a regular lane to demarcate where cyclists should ride.
 * Bicycle boulevard – a low speed street where through-traffic by motor vehicles is restricted while bicycle traffic is encouraged.