Motorcyclist Behaviour on Bends Figure 3. Average speed for left-hand hazard bend sections (L2B3). doi:10.1371/journal.pone.0029978.g003 main effects analysis comparing rider groups at each level of road section). However, when the riders reached section 5, all groups moved back towards the centre line, but due to their early positioning the advanced riders were still significantly closer to the centre than the novice riders (p,0.01). The experienced riders made an extreme shift towards the centre line in section 5 so that their lateral position was no longer different to that of the advanced riders (though they were still statistically indistinguish- able from the novice riders also). Between sections 5 and 6, the advanced riders maintained their central road position whilst the other two rider groups continued to move towards the centre line. Finally, all three groups moved over to the left in the exit spiral (section 7) in preparation for the upcoming right-hand bend. These findings are illustrated in Figure 4. The right panel summarises the results in a schematic fashion. Essentially the advanced riders took a safer approach closer to the centre line, moving out slightly in section 5 to ensure avoidance of the hazard. The novice and experienced riders had to make more pronounced shifts towards the centre line and they achieved a safe position significantly later than the advanced riders. The novice and experience riders exhibited swerving behaviour in response to the hazard whilst the advanced riders were able to make smaller changes to their road position and in more time due to being able to observe the hazard earlier. Figure 4. Lateral position across the seven bend sections for the rider groups. The left panel represents this as bars with standard errors added, while the right panel is a schematised plan view of the data. doi:10.1371/journal.pone.0029978.g004 PLoS ONE | www.plosone.org 6 January 2012 | Volume 7 | Issue 1 | e29978