Motorcyclist Behaviour on Bends Figure 12. Mean lateral position for different sections of the right-hand hazard bend (with standard error bars). doi:10.1371/journal.pone.0029978.g012 across Lap 1 and Lap 2, and across the second and fourth bend, for all seven sections of each curve. Analysis of mean speed revealed a significant main effect of lap (F(1,58) = 11.168; MSe = 145.070; p,0.01), which illustrated that riders were faster on Lap 2 (mean = 49.94 mph) than Lap 1 (mean = 47.99 mph). There was also a significant interaction between bend 6 lap (F(1,58) = 5.234; MSe = 40.622; p,0.05), illustrated in Figure 14. While the interaction looks similar to that noted for the left-hand bends (Figure 6), simple main effects showed that riders were significantly faster on both bends in Lap 2, although the effect was greater for bend 2 (F(1,60) = 14.345; MSe = 15.015; p,0.001) than for bend 4 (F(1,60) = 4.068; MSe = 11.540; p,0.05). Whereas the left-bend hazard ostensibly negated any further increase in speed on L2B4, the right-bend hazard did not fully eliminate the lap effect on bend 4. The analysis of lateral position revealed a main effect of rider group (F(2,58) = 8.329; MSe = 1.732; p,0.01), which showed that experienced riders (mean = 23.328 ft) rode closer to the centre line than advanced riders (mean = 24.885 ft; p,0.01) and novice riders (mean = 24.635 ft; p,0.05). There was a main effect of lap (F(1,58) = 10.704; MSe = 8.285; p,0.01) which revealed that riders were closer to the centre line in Lap 1 (mean = 24.06 ft) than Lap 2 (mean = 24.51 ft). A main effect of section (F(6,348) = 192.168; MSe = 3.890; p,0.001) suggested that riders made a significant change in lateral position between all adjacent sections (p,0.001), always moving towards the centre line. Figure 13. Variance of lateral position for rider groups across the sections of the right-hand hazard bend (with standard error bars). doi:10.1371/journal.pone.0029978.g013 PLoS ONE | www.plosone.org 11 January 2012 | Volume 7 | Issue 1 | e29978