Motorcyclist Behaviour on Bends Figure 16. Variance of lateral position for rider group in Bends 2 and 4 (with standard error bars). doi:10.1371/journal.pone.0029978.g016 only an effect of rider group for bend 4 (F(2,58) = 3.878; MSe = 0.054; p,0.05), with post hoc Scheffe´ tests revealing that experienced riders varied their position more than the novices (Figure 16). There was also a main effect of curve section (F(6,348) = 18.597; MSe = 0.539; p,0.001), and a significant interaction between rider group 6 curve section (F(12,348) = 1.829; MSe = 0.539; p,0.05). As illustrated in Figure 17, both experienced and advanced riders significantly reduced lateral variance from sections 3 to 4 (when passing the apex), and then only advanced riders significantly increased lateral variance between sections 6 and 7 (supported by simple main effects analysis, p,0.05). In contrast, novices maintained the same variance of lateral position across these sections. However, curve section also interacted with bend (F(6,348) = 2.598; MSe = 0.253; p,0.05) and with lap (F(6,348) = 2.316; MSe = 0.279; p,0.05). The first of these interactions was due to increased lateral variance on Bend 4 compared to Bend 2 in the early part of the curve (section 2). The second interaction was due to a general increase in lateral variance on the second Lap immediately following the apex (section 5). As both of these interactions do not involve rider group, and merely describe overall changes in the way Figure 17. Variance of lateral position for rider groups across the right-hand non-hazard bend sections (with standard error bars added). doi:10.1371/journal.pone.0029978.g017 PLoS ONE | www.plosone.org 13 January 2012 | Volume 7 | Issue 1 | e29978