you could get it up to 150mph on the road towards the airport but by the time you arrived at the airport you would probably have been flashed a few times by the speed cameras that would result in your license taken away and probably banned from driving for a few years.
Most bikers dont go for such high speeds they go for the difficult road like the Route Twist and Shek o or even clear water bay, you will see them on the weekends early in the morning or very late at night. Its more fun then trying to reach 150 in a straight line