Stephen wrote: Obviously the plates cover the joins. Because the pontoons float then the angle of the ramp changes as the water level rises and falls. So the ramp slides across the pontoon. Anything but metal would wear out too quick. I hate to say this but maybe speed bumps are the only solution. Some riders are just so stupidly fast through there.
Yes, I had figured out the plates covered the joins and that anything but metal would wear out too quick, but there are about four places on that section of the trail where going from a relatively smooth path onto (generally a downhill section of) pontoon that the yellow metal lip rises about 4cms in a sort of inverted V shape - although it feels higher. If the aim was to slow people it often doesn't work because (a) often those who travel "stupidly fast" have the ability to bunny hop their bike and then continue at speed or (b) it temporarily slows people who then take crazy overtaking risks on the flatter floating sections to make up lost time.