Segregated cycle facilities exist in some areas, allowing cycling without sharing roads with motorized traffic. Cities that are structured that way report a high degree of bicycle usage and low injury rates, such as in the Netherlands. A 2001 study in Edmonton, Alberta, Canada concluded that cyclists found 1 minute of cycling in mixed traffic as onerous as 4.1 minutes on bike lanes or 2.8 minutes on bike paths. A study of cyclists in Washington D.C. found that cyclists were willing to spend on average 20.38 extra minutes per trip to travel on an off-street bicycle trail when the alternative was riding on a street with parked cars. Forester believes segregated cycle facilities to be more dangerous than on-road cycling due to increase risk from crossing conflicts and that, in the case of sidepaths, they can only be used safely by cycling "very slowly".