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Dedicated or segregated cycle facilities are controversial, in particular concerning safety. Proponents say that segregation of cyclists from fast or frequent motorized traffic is necessary to provide a safe and welcoming cycling environment. A 2010 Montreal study found that cycle tracks resulted in fewer injuries when compared to comparable parallel roads with no cycling facilities.〔Lalonde, Michelle. ("Bike paths reduce injuries: study" ) 10 February 2011. 〕 Studies into the risks and benefits of dedicated cycling facilities have drawn differing 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 also been research suggesting that cycling-specific infrastructure raises the risk for cyclists. A 2006 report by the National Cooperative Highway Research Program in the US concludes that "bicycle safety data are difficult to analyze, mostly because bicycle trip data (and thus accident probability per trip) are hard to uncover".〔NCHRP Report 552, 2006, "Guidelines for Analysis of Investment in Bicycle Facilities", National Cooperative Highway Research Program, Transportation research Board of the National Academies, page F-1〕 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== A 1997 study by Moritz of North American bicycle commuters〔http://www.bicyclinglife.com/Library/Moritz1.htm〕 calculated a relative danger of different facilities based on the survey results of "(of crashes ) divided by the (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 "()ot a statistical or random sample of BCs (commuters )." A large study undertaken by S.U. Jensen et al.〔(Road safety and perceived risk of cycle facilities in Copenhagen ), S.U. Jensen, C. Rosenkilde, N Jensen, Road & Park, City of Copenhagen, Presentation to European Cycling Federation AGM 2006〕〔(Bicycle Tracks and Lanes: a Before - After Study ), Søren Underlien Jensen, Trafitec ApS 2007〕 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 number of accidents and injuries increased at intersections but decreased mid-block. These changes in road safety have been estimated taking both general trends in safety and changes in car and cycle traffic into account. 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. In 2009, the University of British Columbia ''Cycling in Cities'' Research Program looked at injury and crash data separated by bicycle facility type and found 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 2010 study in Montreal, Canada authors found 2.5 times as many cyclists rode on the cycle tracks (physically separated bicycle-exclusive paths along roads) compared to the reference roads (a parallel road with approximately the same intersection frequency and cross traffic) and 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 "()ycle tracks lessen, or at least do not increase, crash and injury rates compared to bicycling in the street"〔 A final report from Cycling in Cities in 2012 found that that cycling on segregated tracks had approximately one ninth the risk of cycling on major streets with parked cars and no cycle infrastructure, concluding that, "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%.〔(Prospect Park West Bicycle Path and Traffic Calming ) NYC Department of Transportation. Accessed on 7 February 2011〕 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bikeway safety」の詳細全文を読む スポンサード リンク
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