Wasn't it only last year, or maybe the year before, that a couple died in a bike/sidecar combo on Madeira Drive on a perfectly straight road in the Time Trials thing? Shit happens, and they died what they loved doing. How do you legislate against that?
Prob still allowed for exactly the same reason the Lewes Bonfire thing is still allowed. Because elfen safety haven't yet succeeded in killing it off. Unlike the cheese-rolling-down-a-hill thing that was forced into going 'unofficial' this year.