So its risky - not stupid. The road is flat, wide, and open. Its 4am. There is no possibility of unexpected traffic entry - and if you hit the Berrigan Dr bridge doing 180, you can be back to 100 in an instant before the on ramp.
Better than doing 220 on North Lake Road at 3pm on a Sunday ... something I would never do these days. Funnily enough I was driving a perth wrx members car at the time