There are a few of these locally. I understand what the message is: 'This can be a dangerous piece of road to ride a motorcycle on...with the subtext: particularly if you are 40+ year old manchild vainly trying to relive your teenage years on a recently purchased sport bike/H-D cruiser which you don't have the experience to ride safely ', but the grammar is so contorted it just reads weird...
Sorry I can't find the photo, but many years ago a Scottish newspaper featured a roadside high snow drift and poking up through it was a Kangaroo sign familiar to most Ozzies. Thr caption said that the Scottish Police were quite angry (couldn'e see the humour) and were seeking the Australian culprits - who probably were back home by then. Cheers, Bill in Oz (Not guilty your Honour)